curl (linux parancs)

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A curl linux parancs manual oldala és súgója. A curl egy eszköz, amivel adatokat tölthetünk le egy szerverről, vagy tölthetünk fel rá a program által támogatott protokollok valamelyikével (DICT, FILE, FTP, FTPS, GOPHER, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS, POP3, POP3S, RTMP, RTSP, SCP, SFTP, SMB, SMBS, SMTP, SMTPS, TELNET és TFTP). A parancs felhasználói beavatkozás nélkül működik.

 

 

Man oldal kimenet

man curl
curl(1)                               Curl Manual                               curl(1)

NAME
       curl - transfer a URL

SYNOPSIS
       curl [options] [URL...]

DESCRIPTION
       curl  is a tool to transfer data from or to a server, using one of the supported
       protocols (DICT, FILE, FTP, FTPS, GOPHER, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS,
       POP3,  POP3S,  RTMP,  RTSP, SCP, SFTP, SMB, SMBS, SMTP, SMTPS, TELNET and TFTP).
       The command is designed to work without user interaction.

       curl offers a busload of useful tricks like proxy support, user  authentication,
       FTP upload, HTTP post, SSL connections, cookies, file transfer resume, Metalink,
       and more. As you will see below, the number of  features  will  make  your  head
       spin!

       curl is powered by libcurl for all transfer-related features. See libcurl(3) for
       details.

URL
       The URL syntax is protocol-dependent. You'll find a detailed description in  RFC
       3986.

       You  can  specify  multiple  URLs  or  parts of URLs by writing part sets within
       braces as in:

         http://site.{one,two,three}.com

       or you can get sequences of alphanumeric series by using [] as in:

         ftp://ftp.example.com/file[1-100].txt

         ftp://ftp.example.com/file[001-100].txt    (with leading zeros)

         ftp://ftp.example.com/file[a-z].txt

       Nested sequences are not supported, but you can use several ones  next  to  each
       other:

         http://example.com/archive[1996-1999]/vol[1-4]/part{a,b,c}.html

       You  can specify any amount of URLs on the command line. They will be fetched in
       a sequential manner in the specified order.

       You can specify a step counter for the ranges to get every Nth number or letter:

         http://example.com/file[1-100:10].txt

         http://example.com/file[a-z:2].txt

       When using [] or {} sequences when invoked from a command line prompt, you prob‐
       ably  have  to  put  the  full  URL within double quotes to avoid the shell from
       interfering with it. This also goes for other characters treated  special,  like
       for example '&', '?' and '*'.

       Provide  the  IPv6 zone index in the URL with an escaped percentage sign and the
       interface name. Like in

         http://[fe80::3%25eth0]/

       If you specify URL without protocol:// prefix, curl will attempt to  guess  what
       protocol  you  might  want. It will then default to HTTP but try other protocols
       based on often-used host name prefixes. For example,  for  host  names  starting
       with "ftp." curl will assume you want to speak FTP.

       curl  will  do its best to use what you pass to it as a URL. It is not trying to
       validate it as a syntactically correct URL by any means but is instead very lib‐
       eral with what it accepts.

       curl  will  attempt  to  re-use connections for multiple file transfers, so that
       getting many files from the same server will not do multiple  connects  /  hand‐
       shakes. This improves speed. Of course this is only done on files specified on a
       single command line and cannot be used between separate curl invokes.

PROGRESS METER
       curl normally displays a progress meter during operations, indicating the amount
       of  transferred data, transfer speeds and estimated time left, etc. The progress
       meter displays number of bytes and the speeds are in bytes per second. The  suf‐
       fixes  (k,  M,  G,  T,  P)  are  1024 based. For example 1k is 1024 bytes. 1M is
       1048576 bytes.

       curl displays this data to the terminal by default, so if you invoke curl to  do
       an  operation  and  it  is  about to write data to the terminal, it disables the
       progress meter as otherwise it would mess up the output  mixing  progress  meter
       and response data.

       If you want a progress meter for HTTP POST or PUT requests, you need to redirect
       the response output to a file, using shell redirect (>), -o [file] or similar.

       It is not the same case for FTP upload as that operation does not spit  out  any
       response data to the terminal.

       If  you prefer a progress "bar" instead of the regular meter, -#, --progress-bar
       is your friend.

OPTIONS
       Options start with one or two dashes. Many of the options require an  additional
       value next to them.

       The short "single-dash" form of the options, -d for example, may be used with or
       without a space between it and its value, although a space is a recommended sep‐
       arator.  The  long  "double-dash" form, -d, --data for example, requires a space
       between it and its value.

       Short version options that don't need any additional values can be used  immedi‐
       ately  next  to each other, like for example you can specify all the options -O,
       -L and -v at once as -OLv.

       In general, all boolean options are enabled with --option and yet again disabled
       with --no-option. That is, you use the exact same option name but prefix it with
       "no-". However, in this list we mostly only list and show the  --option  version
       of  them.  (This  concept with --no options was added in 7.19.0. Previously most
       options were toggled on/off on repeated use of the same command line option.)

       --anyauth
              (HTTP) Tells curl to figure out authentication method by itself, and  use
              the  most  secure  one the remote site claims to support. This is done by
              first doing a request and checking the  response-headers,  thus  possibly
              inducing  an  extra network round-trip. This is used instead of setting a
              specific authentication method, which you can do with --basic,  --digest,
              --ntlm, and --negotiate.

              Using --anyauth is not recommended if you do uploads from stdin, since it
              may require data to be sent twice and then the client  must  be  able  to
              rewind.  If  the  need should arise when uploading from stdin, the upload
              operation will fail.

              Used together with -u, --user.

              See also --proxy-anyauth and --basic and --digest.

       -a, --append
              (FTP SFTP) When used in an upload, this makes curl append to  the  target
              file instead of overwriting it. If the remote file doesn't exist, it will
              be created.  Note that this flag is ignored by some SFTP servers (includ‐
              ing OpenSSH).

       --basic
              (HTTP)  Tells curl to use HTTP Basic authentication with the remote host.
              This is the default and this option is usually pointless, unless you  use
              it  to override a previously set option that sets a different authentica‐
              tion method (such as --ntlm, --digest, or --negotiate).

              Used together with -u, --user.

              See also --proxy-basic.

       --cacert <CA certificate>
              (TLS) Tells curl to use the specified  certificate  file  to  verify  the
              peer.  The  file may contain multiple CA certificates. The certificate(s)
              must be in PEM format. Normally curl is built to use a default  file  for
              this, so this option is typically used to alter that default file.

              curl  recognizes the environment variable named 'CURL_CA_BUNDLE' if it is
              set, and uses the given path as a path to a CA cert bundle.  This  option
              overrides that variable.

              The  windows  version of curl will automatically look for a CA certs file
              named ´curl-ca-bundle.crt´, either in the same directory as curl.exe,  or
              in the Current Working Directory, or in any folder along your PATH.

              If  curl is built against the NSS SSL library, the NSS PEM PKCS#11 module
              (libnsspem.so) needs to be available for this option to work properly.

              (iOS and macOS only) If curl is built against Secure Transport, then this
              option  is  supported  for backward compatibility with other SSL engines,
              but it should not be set. If the option is not set, then  curl  will  use
              the  certificates  in  the  system  and user Keychain to verify the peer,
              which is the preferred method of verifying the peer's certificate chain.

              If this option is used several times, the last one will be used.

       --capath <dir>
              (TLS) Tells curl to use the specified certificate directory to verify the
              peer.  Multiple  paths  can be provided by separating them with ":" (e.g.
              "path1:path2:path3"). The certificates must be in PEM format, and if curl
              is  built  against  OpenSSL, the directory must have been processed using
              the c_rehash utility supplied with  OpenSSL.  Using  --capath  can  allow
              OpenSSL-powered  curl  to make SSL-connections much more efficiently than
              using --cacert if the --cacert file contains many CA certificates.

              If this option is set, the default capath value will be ignored,  and  if
              it is used several times, the last one will be used.

       --cert-status
              (TLS)  Tells curl to verify the status of the server certificate by using
              the Certificate Status Request (aka. OCSP stapling) TLS extension.

              If this option is enabled and the server sends an invalid (e.g.  expired)
              response,  if  the response suggests that the server certificate has been
              revoked, or no response at all is received, the verification fails.

              This is currently only implemented in the OpenSSL, GnuTLS and  NSS  back‐
              ends.

              Added in 7.41.0.

       --cert-type <type>
              (TLS)  Tells  curl  what certificate type the provided certificate is in.
              PEM, DER and ENG are recognized types.  If not specified, PEM is assumed.

              If this option is used several times, the last one will be used.

              See also -E, --cert and --key and --key-type.

       -E, --cert <certificate[:password]>
              (TLS) Tells curl to use the specified client certificate file  when  get‐
              ting  a file with HTTPS, FTPS or another SSL-based protocol. The certifi‐
              cate must be in PKCS#12 format if using Secure Transport, or  PEM  format
              if  using any other engine.  If the optional password isn't specified, it
              will be queried for on the terminal. Note  that  this  option  assumes  a
              "certificate"  file  that  is  the private key and the client certificate
              concatenated! See -E, --cert and --key to specify them independently.

              If curl is built against the NSS SSL library then this  option  can  tell
              curl  the  nickname  of  the  certificate  to use within the NSS database
              defined  by   the   environment   variable   SSL_DIR   (or   by   default
              /etc/pki/nssdb).  If  the NSS PEM PKCS#11 module (libnsspem.so) is avail‐
              able then PEM files may be loaded. If you want to use  a  file  from  the
              current  directory, please precede it with "./" prefix, in order to avoid
              confusion with a nickname.  If the nickname contains ":", it needs to  be
              preceded  by  "\" so that it is not recognized as password delimiter.  If
              the nickname contains "\", it needs to be escaped as "\\" so that  it  is
              not recognized as an escape character.

              (iOS  and macOS only) If curl is built against Secure Transport, then the
              certificate string can either be the name of a certificate/private key in
              the system or user keychain, or the path to a PKCS#12-encoded certificate
              and private key. If you want to use a file from  the  current  directory,
              please  precede  it  with "./" prefix, in order to avoid confusion with a
              nickname.

              If this option is used several times, the last one will be used.

              See also --cert-type and --key and --key-type.

       --ciphers <list of ciphers>
              (TLS) Specifies which ciphers to use  in  the  connection.  The  list  of
              ciphers must specify valid ciphers. Read up on SSL cipher list details on
              this URL:

               https://www.openssl.org/docs/apps/ciphers.html

              NSS ciphers are done differently than OpenSSL and GnuTLS. The  full  list
              of NSS ciphers is in the NSSCipherSuite entry at this URL:

               https://git.fedora‐
              hosted.org/cgit/mod_nss.git/plain/docs/mod_nss.html#Directives

              If this option is used several times, the last one will be used.

       --compressed
              (HTTP) Request a compressed response using one  of  the  algorithms  curl
              supports, and save the uncompressed document.  If this option is used and
              the server sends an unsupported encoding, curl will report an error.

       -K, --config <file>
              Specify which config file to read curl arguments from. The config file is
              a  text  file  in  which command line arguments can be written which then
              will be used as if they were written on the actual command line.

              Options and their parameters must be specified on the  same  config  file
              line,  separated  by  whitespace,  colon, or the equals sign. Long option
              names can optionally be given in the config file without the initial dou‐
              ble dashes and if so, the colon or equals characters can be used as sepa‐
              rators. If the option is specified with one or two dashes, there  can  be
              no colon or equals character between the option and its parameter.

              If the parameter is to contain whitespace, the parameter must be enclosed
              within quotes. Within double quotes, the following escape  sequences  are
              available:  \\,  \",  \t,  \n, \r and \v. A backslash preceding any other
              letter is ignored. If the first column of a config line is a '#'  charac‐
              ter,  the  rest  of the line will be treated as a comment. Only write one
              option per physical line in the config file.

              Specify the filename to -K, --config as '-' to make curl  read  the  file
              from stdin.

              Note  that  to  be  able to specify a URL in the config file, you need to
              specify it using the --url option, and not by simply writing the  URL  on
              its own line. So, it could look similar to this:

              url = "https://curl.haxx.se/docs/"

              When curl is invoked, it always (unless -q, --disable is used) checks for
              a default config file and uses it if found. The default  config  file  is
              checked for in the following places in this order:

              1)  curl  tries to find the "home dir": It first checks for the CURL_HOME
              and then the HOME environment variables. Failing that, it uses getpwuid()
              on  Unix-like  systems (which returns the home dir given the current user
              in your system). On Windows, it then checks for the APPDATA variable,  or
              as a last resort the '%USERPROFILE%\Application Data'.

              2) On windows, if there is no _curlrc file in the home dir, it checks for
              one in the same dir the curl executable is placed. On Unix-like  systems,
              it will simply try to load .curlrc from the determined home dir.

              # --- Example file ---
              # this is a comment
              url = "example.com"
              output = "curlhere.html"
              user-agent = "superagent/1.0"

              # and fetch another URL too
              url = "example.com/docs/manpage.html"
              -O
              referer = "http://nowhereatall.example.com/"
              # --- End of example file ---

              This option can be used multiple times to load multiple config files.

       --connect-timeout <seconds>
              Maximum  time  in seconds that you allow curl's connection to take.  This
              only limits the connection phase, so if curl connects  within  the  given
              period  it  will  continue  - if not it will exit.  Since version 7.32.0,
              this option accepts decimal values.

              If this option is used several times, the last one will be used.

              See also -m, --max-time.

       --connect-to <HOST1:PORT1:HOST2:PORT2>

              For a request  to  the  given  HOST:PORT  pair,  connect  to  CONNECT-TO-
              HOST:CONNECT-TO-PORT instead.  This option is suitable to direct requests
              at a specific server, e.g. at a specific cluster node  in  a  cluster  of
              servers.   This  option is only used to establish the network connection.
              It does NOT affect the hostname/port that is used for TLS/SSL (e.g.  SNI,
              certificate  verification)  or for the application protocols.  "host" and
              "port" may be the empty string, meaning  "any  host/port".   "connect-to-
              host"  and  "connect-to-port"  may also be the empty string, meaning "use
              the request's original host/port".

              This option can be used many times to add many connect rules.

              See also --resolve and -H, --header. Added in 7.49.0.

       -C, --continue-at <offset>
              Continue/Resume a previous file transfer at the given offset.  The  given
              offset  is  the exact number of bytes that will be skipped, counting from
              the beginning of the source file before it is transferred to the destina‐
              tion.  If used with uploads, the FTP server command SIZE will not be used
              by curl.

              Use "-C -" to tell curl to automatically find out where/how to resume the
              transfer. It then uses the given output/input files to figure that out.

              If this option is used several times, the last one will be used.

              See also -r, --range.

       -c, --cookie-jar <filename>
              (HTTP)  Specify  to which file you want curl to write all cookies after a
              completed operation. Curl writes all cookies from  its  in-memory  cookie
              storage  to  the  given  file at the end of operations. If no cookies are
              known, no data will be written. The file will be written using  the  Net‐
              scape cookie file format. If you set the file name to a single dash, "-",
              the cookies will be written to stdout.

              This command line option will activate the cookie engine that makes  curl
              record  and  use  cookies.  Another  way to activate it is to use the -b,
              --cookie option.

              If the cookie jar can't be created or written to, the whole  curl  opera‐
              tion won't fail or even report an error clearly. Using -v, --verbose will
              get a warning displayed, but that is the only visible  feedback  you  get
              about this possibly lethal situation.

              If  this  option is used several times, the last specified file name will
              be used.

       -b, --cookie <data>
              (HTTP) Pass the data to the HTTP server in the Cookie header. It is  sup‐
              posedly  the  data previously received from the server in a "Set-Cookie:"
              line.  The data should be in the format "NAME1=VALUE1; NAME2=VALUE2".

              If no '=' symbol is used in the argument, it  is  instead  treated  as  a
              filename  to  read  previously stored cookie from. This option also acti‐
              vates the cookie engine which will make  curl  record  incoming  cookies,
              which  may  be  handy  if  you're  using this in combination with the -L,
              --location option or do multiple URL transfers on the same invoke.

              The file format of the file to read cookies from  should  be  plain  HTTP
              headers (Set-Cookie style) or the Netscape/Mozilla cookie file format.

              The  file  specified  with -b, --cookie is only used as input. No cookies
              will be written to the file. To store cookies, use the  -c,  --cookie-jar
              option.

              Exercise  caution if you are using this option and multiple transfers may
              occur.  If you use the NAME1=VALUE1; format, or in a file  use  the  Set-
              Cookie format and don't specify a domain, then the cookie is sent for any
              domain (even after redirects are followed) and cannot be  modified  by  a
              server-set  cookie.  If  the cookie engine is enabled and a server sets a
              cookie of the same name then both will be sent on a  future  transfer  to
              that server, likely not what you intended.  To address these issues set a
              domain in Set-Cookie (doing that will include sub  domains)  or  use  the
              Netscape format.

              If this option is used several times, the last one will be used.

              Users  very often want to both read cookies from a file and write updated
              cookies back to a file, so using both -b, --cookie and  -c,  --cookie-jar
              in the same command line is common.

       --create-dirs
              When  used  in conjunction with the -o, --output option, curl will create
              the necessary local directory hierarchy as needed.  This  option  creates
              the  dirs  mentioned  with  the -o, --output option, nothing else. If the
              --output file name uses no dir or if the dirs it mentions already  exist,
              no dir will be created.

              To  create  remote  directories when using FTP or SFTP, try --ftp-create-
              dirs.

       --crlf (FTP SMTP) Convert LF to CRLF in upload. Useful for MVS (OS/390).

              (SMTP added in 7.40.0)

       --crlfile <file>
              (TLS) Provide a file using PEM format with a Certificate Revocation  List
              that may specify peer certificates that are to be considered revoked.

              If this option is used several times, the last one will be used.

              Added in 7.19.7.

       --data-ascii <data>
              (HTTP) This is just an alias for -d, --data.

       --data-binary <data>
              (HTTP)  This  posts  data  exactly  as specified with no extra processing
              whatsoever.

              If you start the data with the letter @, the rest should be  a  filename.
              Data  is  posted in a similar manner as -d, --data does, except that new‐
              lines and carriage returns are preserved and conversions are never done.

              If this option is used several times, the ones following the  first  will
              append data as described in -d, --data.

       --data-raw <data>
              (HTTP)  This  posts  data similarly to -d, --data but without the special
              interpretation of the @ character.

              See also -d, --data. Added in 7.43.0.

       --data-urlencode <data>
              (HTTP) This posts data, similar to the other -d, --data options with  the
              exception that this performs URL-encoding.

              To be CGI-compliant, the <data> part should begin with a name followed by
              a separator and a content specification. The <data> part can be passed to
              curl using one of the following syntaxes:

              content
                     This  will make curl URL-encode the content and pass that on. Just
                     be careful so that the content doesn't contain any = or @ symbols,
                     as  that  will  then  make the syntax match one of the other cases
                     below!

              =content
                     This will make curl URL-encode the content and pass that  on.  The
                     preceding = symbol is not included in the data.

              name=content
                     This  will make curl URL-encode the content part and pass that on.
                     Note that the name part is expected to be URL-encoded already.

              @filename
                     This will make curl load data from the given file  (including  any
                     newlines), URL-encode that data and pass it on in the POST.

              name@filename
                     This  will  make curl load data from the given file (including any
                     newlines), URL-encode that data and pass it on in  the  POST.  The
                     name  part  gets  an equal sign appended, resulting in name=urlen‐
                     coded-file-content. Note that the name  is  expected  to  be  URL-
                     encoded already.

       See also -d, --data and --data-raw. Added in 7.18.0.

       -d, --data <data>
              (HTTP)  Sends the specified data in a POST request to the HTTP server, in
              the same way that a browser does when a user has filled in an  HTML  form
              and  presses  the submit button. This will cause curl to pass the data to
              the  server  using  the  content-type  application/x-www-form-urlencoded.
              Compare to -F, --form.

              --data-raw  is almost the same but does not have a special interpretation
              of the @ character. To post data purely binary, you  should  instead  use
              the  --data-binary  option.   To URL-encode the value of a form field you
              may use --data-urlencode.

              If any of these options is used more than once on the same command  line,
              the  data  pieces  specified  will  be  merged together with a separating
              &-symbol. Thus, using '-d name=daniel -d skill=lousy'  would  generate  a
              post chunk that looks like 'name=daniel&skill=lousy'.

              If  you  start the data with the letter @, the rest should be a file name
              to read the data from, or - if you want curl to read the data from stdin.
              Multiple files can also be specified. Posting data from a file named from
              a file like that, carriage returns and newlines will be stripped out.  If
              you  don't  want  the  @  character  to have a special interpretation use
              --data-raw instead.

              See also --data-binary and --data-urlencode and --data-raw.  This  option
              overrides -F, --form and -I, --head and --upload.

       --delegation <LEVEL>
              (GSS/kerberos)  Set  LEVEL to tell the server what it is allowed to dele‐
              gate when it comes to user credentials.

              none   Don't allow any delegation.

              policy Delegates if and only if the OK-AS-DELEGATE flag  is  set  in  the
                     Kerberos service ticket, which is a matter of realm policy.

              always Unconditionally allow the server to delegate.

       --digest
              (HTTP)  Enables  HTTP  Digest  authentication.  This is an authentication
              scheme that prevents the password from being sent over the wire in  clear
              text.  Use  this  in combination with the normal -u, --user option to set
              user name and password.

              If this option is used several times, only the first one is used.

              See also -u, --user and --proxy-digest and --anyauth. This  option  over‐
              rides --basic and --ntlm and --negotiate.

       --disable-eprt
              (FTP)  Tell  curl  to  disable the use of the EPRT and LPRT commands when
              doing active FTP transfers. Curl will normally always  first  attempt  to
              use  EPRT, then LPRT before using PORT, but with this option, it will use
              PORT right away. EPRT and LPRT are extensions to the original FTP  proto‐
              col,  and may not work on all servers, but they enable more functionality
              in a better way than the traditional PORT command.

              --eprt can be used to explicitly enable EPRT again and  --no-eprt  is  an
              alias for --disable-eprt.

              If  the server is accessed using IPv6, this option will have no effect as
              EPRT is necessary then.

              Disabling EPRT only changes the active behavior. If you want to switch to
              passive  mode  you need to not use -P, --ftp-port or force it with --ftp-
              pasv.

       --disable-epsv
              (FTP) (FTP) Tell curl to disable the use of the EPSV command  when  doing
              passive  FTP  transfers.  Curl  will normally always first attempt to use
              EPSV before PASV, but with this option, it will not try using EPSV.

              --epsv can be used to explicitly enable EPSV again and  --no-epsv  is  an
              alias for --disable-epsv.

              If the server is an IPv6 host, this option will have no effect as EPSV is
              necessary then.

              Disabling EPSV only changes the passive behavior. If you want  to  switch
              to active mode you need to use -P, --ftp-port.

       -q, --disable
              If  used  as  the  first parameter on the command line, the curlrc config
              file will not be read and used. See the -K, --config for details  on  the
              default config file search path.

       --dns-interface <interface>
              (DNS)  Tell  curl to send outgoing DNS requests through <interface>. This
              option is a counterpart to --interface (which does not affect  DNS).  The
              supplied string must be an interface name (not an address).

              See  also  --dns-ipv4-addr  and --dns-ipv6-addr. --dns-interface requires
              that the underlying libcurl was built to support c-ares. Added in 7.33.0.

       --dns-ipv4-addr <address>
              (DNS) Tell curl to bind to <ip-address> when making IPv4 DNS requests, so
              that the DNS requests originate from this address. The argument should be
              a single IPv4 address.

              See also --dns-interface and  --dns-ipv6-addr.  --dns-ipv4-addr  requires
              that the underlying libcurl was built to support c-ares. Added in 7.33.0.

       --dns-ipv6-addr <address>
              (DNS) Tell curl to bind to <ip-address> when making IPv6 DNS requests, so
              that the DNS requests originate from this address. The argument should be
              a single IPv6 address.

              See  also  --dns-interface  and --dns-ipv4-addr. --dns-ipv6-addr requires
              that the underlying libcurl was built to support c-ares. Added in 7.33.0.

       --dns-servers <addresses>
              Set the list of DNS servers to be used instead  of  the  system  default.
              The  list  of  IP addresses should be separated with commas. Port numbers
              may also optionally be given as :<port-number> after each IP address.

              --dns-servers requires that the underlying libcurl was built  to  support
              c-ares. Added in 7.33.0.

       -D, --dump-header <filename>
              (HTTP FTP) Write the received protocol headers to the specified file.

              This  option  is  handy to use when you want to store the headers that an
              HTTP site sends to you. Cookies from the headers could then be read in  a
              second  curl  invocation  by  using  the  -b,  --cookie  option!  The -c,
              --cookie-jar option is a better way to store cookies.

              When used in FTP, the FTP server  response  lines  are  considered  being
              "headers" and thus are saved there.

              If this option is used several times, the last one will be used.

              See also -o, --output.

       --egd-file <file>
              (TLS)  Specify  the path name to the Entropy Gathering Daemon socket. The
              socket is used to seed the random engine for SSL connections.

              See also --random-file.

       --engine <name>
              (TLS) Select the OpenSSL crypto engine to use for cipher operations.  Use
              --engine  list to print a list of build-time supported engines. Note that
              not all (or none) of the engines may be available at run-time.

       --environment
              Sets a range of environment variables, using the names the  -w,  --write-
              out  option  supports,  to  allow easier extraction of useful information
              after having run curl.

              --environment requires that the underlying libcurl was built  to  support
              RISC OS.

       --expect100-timeout <seconds>
              (HTTP) Maximum time in seconds that you allow curl to wait for a 100-con‐
              tinue response when curl emits an Expects:  100-continue  header  in  its
              request.  By default curl will wait one second. This option accepts deci‐
              mal values! When curl stops waiting, it will continue as if the  response
              has been received.

              See also --connect-timeout. Added in 7.47.0.

       --fail-early
              Fail and exit on first detected error.

              When  curl  is used to do multiple transfers on the command line, it will
              attempt to operate on each given URL, one by one.  By  default,  it  will
              ignore  errors  if  there  are more URLs given and the last URL's success
              will determine the error code curl returns. So  early  failures  will  be
              "hidden" by subsequent successful transfers.

              Using  this option, curl will instead return an error on the first trans‐
              fers that fails, independent on the amount of more URLs that are given on
              the command line. This way, no transfer failures go undetected by scripts
              and similar.

              This option will apply for all given URLs even if you use -:, --next.

              Added in 7.52.0.

       -f, --fail
              (HTTP) Fail silently (no output at all) on server errors. This is  mostly
              done to better enable scripts etc to better deal with failed attempts. In
              normal cases when an HTTP server fails to deliver a document, it  returns
              an  HTML  document  stating so (which often also describes why and more).
              This flag will prevent curl from outputting that and return error 22.

              This method is not fail-safe and there are occasions where non-successful
              response  codes  will  slip  through,  especially  when authentication is
              involved (response codes 401 and 407).

       --false-start
              (TLS) Tells curl to use false start during the TLS handshake. False start
              is  a  mode where a TLS client will start sending application data before
              verifying the server's Finished message, thus saving a  round  trip  when
              performing a full handshake.

              This  is  currently  only implemented in the NSS and Secure Transport (on
              iOS 7.0 or later, or OS X 10.9 or later) backends.

              Added in 7.42.0.

       --form-string <name=string>
              (HTTP) Similar to -F, --form except that the value string for  the  named
              parameter  is  used  literally.  Leading  '@' and '<' characters, and the
              ';type=' string in the value have no special meaning. Use this in prefer‐
              ence  to  -F, --form if there's any possibility that the string value may
              accidentally trigger the '@' or '<' features of -F, --form.

              See also -F, --form.

       -F, --form <name=content>
              (HTTP) This lets curl emulate a  filled-in  form  in  which  a  user  has
              pressed  the  submit button. This causes curl to POST data using the Con‐
              tent-Type multipart/form-data according to RFC 2388. This enables upload‐
              ing of binary files etc. To force the 'content' part to be a file, prefix
              the file name with an @ sign. To just get the content part from  a  file,
              prefix the file name with the symbol <. The difference between @ and < is
              then that @ makes a file get attached in the post as a file upload, while
              the  <  makes  a text field and just get the contents for that text field
              from a file.

              Example: to send an image to a server, where 'profile' is the name of the
              form-field to which portrait.jpg will be the input:

               curl -F profile=@portrait.jpg https://example.com/upload.cgi

              To read content from stdin instead of a file, use - as the filename. This
              goes for both @ and < constructs. Unfortunately it does not support read‐
              ing  the  file  from  a  named pipe or similar, as it needs the full size
              before the transfer starts.

              You can also tell curl what Content-Type to use by using  'type=',  in  a
              manner similar to:

               curl -F "web=@index.html;type=text/html" example.com

              or

               curl -F "name=daniel;type=text/foo" example.com

              You  can  also  explicitly change the name field of a file upload part by
              setting filename=, like this:

               curl -F "file=@localfile;filename=nameinpost" example.com

              If filename/path contains ',' or ';', it must be quoted by  double-quotes
              like:

               curl -F "file=@\"localfile\";filename=\"nameinpost\"" example.com

              or

               curl -F 'file=@"localfile";filename="nameinpost"' example.com

              Note that if a filename/path is quoted by double-quotes, any double-quote
              or backslash within the filename must be escaped by backslash.

              See further examples and details in the MANUAL.

              This option can be used multiple times.

              This option overrides -d, --data and -I, --head and --upload.

       --ftp-account <data>
              (FTP) When an FTP server asks for "account  data"  after  user  name  and
              password has been provided, this data is sent off using the ACCT command.

              If this option is used several times, the last one will be used.

              Added in 7.13.0.

       --ftp-alternative-to-user <command>
              (FTP)  If authenticating with the USER and PASS commands fails, send this
              command.  When connecting to Tumbleweed's Secure  Transport  server  over
              FTPS  using  a client certificate, using "SITE AUTH" will tell the server
              to retrieve the username from the certificate.

              Added in 7.15.5.

       --ftp-create-dirs
              (FTP SFTP) When an FTP or SFTP URL/operation uses  a  path  that  doesn't
              currently  exist on the server, the standard behavior of curl is to fail.
              Using this option, curl will instead attempt to create  missing  directo‐
              ries.

              See also --create-dirs.

       --ftp-method <method>
              (FTP)  Control  what  method curl should use to reach a file on an FTP(S)
              server. The method argument should be one of the following alternatives:

              multicwd
                     curl does a single CWD operation for each path part in  the  given
                     URL.  For  deep hierarchies this means very many commands. This is
                     how RFC 1738 says it should be done. This is the default  but  the
                     slowest behavior.

              nocwd  curl  does  no  CWD  at all. curl will do SIZE, RETR, STOR etc and
                     give a full path to the server for all these commands. This is the
                     fastest behavior.

              singlecwd
                     curl does one CWD with the full target directory and then operates
                     on the file "normally" (like in the multicwd case). This is  some‐
                     what  more  standards  compliant than 'nocwd' but without the full
                     penalty of 'multicwd'.

       Added in 7.15.1.

       --ftp-pasv
              (FTP) Use passive mode for the data connection. Passive is  the  internal
              default  behavior, but using this option can be used to override a previ‐
              ous -P, --ftp-port option.

              If this option is used several times, only the first one is used. Undoing
              an enforced passive really isn't doable but you must then instead enforce
              the correct -P, --ftp-port again.

              Passive mode means that curl will try the EPSV  command  first  and  then
              PASV, unless --disable-epsv is used.

              See also --disable-epsv. Added in 7.11.0.

       -P, --ftp-port <address>
              (FTP)  Reverses the default initiator/listener roles when connecting with
              FTP. This option makes curl use active mode. curl then tells  the  server
              to connect back to the client's specified address and port, while passive
              mode asks the server to setup an IP address and port for  it  to  connect
              to. <address> should be one of:

              interface
                     i.e "eth0" to specify which interface's IP address you want to use
                     (Unix only)

              IP address
                     i.e "192.168.10.1" to specify the exact IP address

              host name
                     i.e "my.host.domain" to specify the machine

              -      make curl pick the same IP address that is already  used  for  the
                     control connection

       If this option is used several times, the last one will be used. Disable the use
       of PORT with --ftp-pasv. Disable the attempt to use the EPRT command instead  of
       PORT by using --disable-eprt. EPRT is really PORT++.

       Since  7.19.5,  you  can append ":[start]-[end]" to the right of the address, to
       tell curl what TCP port range to use. That means you specify a port range,  from
       a  lower  to a higher number. A single number works as well, but do note that it
       increases the risk of failure since the port may not be available.

       See also --ftp-pasv and --disable-eprt.

       --ftp-pret
              (FTP) Tell curl to send a PRET command before PASV  (and  EPSV).  Certain
              FTP  servers, mainly drftpd, require this non-standard command for direc‐
              tory listings as well as up and downloads in PASV mode.

              Added in 7.20.0.

       --ftp-skip-pasv-ip
              (FTP) Tell curl to not use the IP address  the  server  suggests  in  its
              response  to  curl's PASV command when curl connects the data connection.
              Instead curl will re-use the same IP address it already uses for the con‐
              trol connection.

              This option has no effect if PORT, EPRT or EPSV is used instead of PASV.

              See also --ftp-pasv. Added in 7.14.2.

       --ftp-ssl-ccc-mode <active/passive>
              (FTP) Sets the CCC mode. The passive mode will not initiate the shutdown,
              but instead wait for the server to do it, and will not reply to the shut‐
              down  from  the  server. The active mode initiates the shutdown and waits
              for a reply from the server.

              See also --ftp-ssl-ccc. Added in 7.16.2.

       --ftp-ssl-ccc
              (FTP) Use CCC (Clear Command Channel) Shuts down the SSL/TLS layer  after
              authenticating.  The  rest  of  the control channel communication will be
              unencrypted. This allows NAT routers to follow the FTP  transaction.  The
              default mode is passive.

              See also --ssl and --ftp-ssl-ccc-mode. Added in 7.16.1.

       --ftp-ssl-control
              (FTP)  Require  SSL/TLS  for  the  FTP login, clear for transfer.  Allows
              secure authentication, but non-encrypted data transfers  for  efficiency.
              Fails the transfer if the server doesn't support SSL/TLS.

              Added in 7.16.0.

       -G, --get
              When  used,  this  option  will  make all data specified with -d, --data,
              --data-binary or --data-urlencode to be  used  in  an  HTTP  GET  request
              instead  of  the POST request that otherwise would be used. The data will
              be appended to the URL with a '?' separator.

              If used in combination with -I, --head, the POST  data  will  instead  be
              appended to the URL with a HEAD request.

              If this option is used several times, only the first one is used. This is
              because undoing a GET doesn't make sense, but  you  should  then  instead
              enforce the alternative method you prefer.

       -g, --globoff
              This  option  switches  off  the "URL globbing parser". When you set this
              option, you can specify URLs that contain the letters {}[] without having
              them  being  interpreted  by curl itself. Note that these letters are not
              normal legal URL contents but they should be encoded according to the URI
              standard.

       -I, --head
              (HTTP  FTP FILE) Fetch the headers only! HTTP-servers feature the command
              HEAD which this uses to get nothing but the header of  a  document.  When
              used on an FTP or FILE file, curl displays the file size and last modifi‐
              cation time only.

       -H, --header <header>
              (HTTP) Extra header to include in the request  when  sending  HTTP  to  a
              server.  You  may  specify  any number of extra headers. Note that if you
              should add a custom header that has the same name as one of the  internal
              ones  curl  would use, your externally set header will be used instead of
              the internal one. This allows you to make even trickier stuff  than  curl
              would  normally do. You should not replace internally set headers without
              knowing perfectly well what you're doing. Remove an  internal  header  by
              giving  a  replacement without content on the right side of the colon, as
              in: -H "Host:". If you send the custom  header  with  no-value  then  its
              header must be terminated with a semicolon, such as -H "X-Custom-Header;"
              to send "X-Custom-Header:".

              curl will make sure that each header you add/replace  is  sent  with  the
              proper  end-of-line marker, you should thus not add that as a part of the
              header content: do not add newlines or carriage returns, they  will  only
              mess things up for you.

              See also the -A, --user-agent and -e, --referer options.

              Starting  in  7.37.0,  you  need  --proxy-header  to  send custom headers
              intended for a proxy.

              Example:

               curl -H "X-First-Name: Joe" http://example.com/

              WARNING: headers set with this option will be set in all requests -  even
              after  redirects  are  followed, like when told with -L, --location. This
              can lead to the header being sent to other hosts than the original  host,
              so  sensitive headers should be used with caution combined with following
              redirects.

              This option can be used multiple  times  to  add/replace/remove  multiple
              headers.

       -h, --help
              Usage  help.  This  lists  all  current command line options with a short
              description.

       --hostpubmd5 <md5>
              (SFTP SCP) Pass a string containing 32  hexadecimal  digits.  The  string
              should  be the 128 bit MD5 checksum of the remote host's public key, curl
              will refuse the connection with the host unless the md5sums match.

              Added in 7.17.1.

       -0, --http1.0
              (HTTP) Tells curl to use HTTP version 1.0 instead of using its internally
              preferred HTTP version.

              This option overrides --http1.1 and --http2.

       --http1.1
              (HTTP) Tells curl to use HTTP version 1.1.

              This option overrides -0, --http1.0 and --http2. Added in 7.33.0.

       --http2-prior-knowledge
              (HTTP) Tells curl to issue its non-TLS HTTP requests using HTTP/2 without
              HTTP/1.1 Upgrade. It requires prior knowledge that  the  server  supports
              HTTP/2  straight  away.  HTTPS requests will still do HTTP/2 the standard
              way with negotiated protocol version in the TLS handshake.

              --http2-prior-knowledge requires that the underlying libcurl was built to
              support  HTTP/2.  This  option  overrides --http1.1 and -0, --http1.0 and
              --http2. Added in 7.49.0.

       --http2
              (HTTP) Tells curl to use HTTP version 2.

              See also --no-alpn. --http2 requires  that  the  underlying  libcurl  was
              built  to  support  HTTP/2.  This  option  overrides  --http1.1  and  -0,
              --http1.0 and --http2-prior-knowledge. Added in 7.33.0.

       --ignore-content-length
              (FTP HTTP) For HTTP, Ignore the Content-Length header. This  is  particu‐
              larly  useful for servers running Apache 1.x, which will report incorrect
              Content-Length for files larger than 2 gigabytes.

              For FTP (since 7.46.0), skip the RETR command  to  figure  out  the  size
              before downloading a file.

       -i, --include
              Include  the  HTTP-header  in the output. The HTTP-header includes things
              like server-name, date of the document, HTTP-version and more...

              See also -v, --verbose.

       -k, --insecure
              (TLS) This option explicitly allows curl to perform "insecure"  SSL  con‐
              nections  and  transfers.  All  SSL  connections are attempted to be made
              secure by using the CA certificate  bundle  installed  by  default.  This
              makes all connections considered "insecure" fail unless -k, --insecure is
              used.

              See this online resource for further details:
               https://curl.haxx.se/docs/sslcerts.html

       --interface <name>

              Perform an operation using a specified interface. You can enter interface
              name, IP address or host name. An example could look like:

               curl --interface eth0:1 https://www.example.com/

              If this option is used several times, the last one will be used.

              See also --dns-interface.

       -4, --ipv4
              This  option  tells curl to resolve names to IPv4 addresses only, and not
              for example try IPv6.

              See also --http1.1 and --http2. This option overrides -6, --ipv6.

       -6, --ipv6
              This option tells curl to resolve names to IPv6 addresses only,  and  not
              for example try IPv4.

              See also --http1.1 and --http2. This option overrides -6, --ipv6.

       -j, --junk-session-cookies
              (HTTP)  When  curl is told to read cookies from a given file, this option
              will make it discard all "session cookies". This will basically have  the
              same  effect as if a new session is started. Typical browsers always dis‐
              card session cookies when they're closed down.

              See also -b, --cookie and -c, --cookie-jar.

       --keepalive-time <seconds>
              This option sets the time a connection needs to remain idle before  send‐
              ing keepalive probes and the time between individual keepalive probes. It
              is currently effective on operating systems offering the TCP_KEEPIDLE and
              TCP_KEEPINTVL socket options (meaning Linux, recent AIX, HP-UX and more).
              This option has no effect if --no-keepalive is used.

              If this option is used several times, the  last  one  will  be  used.  If
              unspecified, the option defaults to 60 seconds.

              Added in 7.18.0.

       --key-type <type>
              (TLS)  Private key file type. Specify which type your --key provided pri‐
              vate key is. DER, PEM, and ENG are supported. If not  specified,  PEM  is
              assumed.

              If this option is used several times, the last one will be used.

       --key <key>
              (TLS  SSH)  Private key file name. Allows you to provide your private key
              in this separate file. For SSH, if not specified, curl tries the  follow‐
              ing candidates in order:

              If this option is used several times, the last one will be used.

       --krb <level>
              (FTP)  Enable  Kerberos authentication and use. The level must be entered
              and should be one  of  'clear',  'safe',  'confidential',  or  'private'.
              Should  you  use a level that is not one of these, 'private' will instead
              be used.

              If this option is used several times, the last one will be used.

              --krb requires that the underlying libcurl was built to support Kerberos.

       --libcurl <file>
              Append this option to any ordinary curl command line, and you will get  a
              libcurl-using  C source code written to the file that does the equivalent
              of what your command-line operation does!

              If this option is used several times, the last given file  name  will  be
              used.

              Added in 7.16.1.

       --limit-rate <speed>
              Specify  the  maximum transfer rate you want curl to use - for both down‐
              loads and uploads. This feature is useful if you have a limited pipe  and
              you'd  like  your  transfer  not to use your entire bandwidth. To make it
              slower than it otherwise would be.

              The given speed is measured in bytes/second, unless a suffix is appended.
              Appending  'k' or 'K' will count the number as kilobytes, 'm' or M' makes
              it megabytes, while 'g' or 'G' makes it gigabytes. Examples: 200K, 3m and
              1G.

              If  you  also  use  the  -Y,  --speed-limit option, that option will take
              precedence and might cripple the rate-limiting slightly, to help  keeping
              the speed-limit logic working.

              If this option is used several times, the last one will be used.

       -l, --list-only
              (FTP  POP3)  (FTP)  When  listing  an FTP directory, this switch forces a
              name-only view. This is especially useful if the user wants  to  machine-
              parse  the  contents  of an FTP directory since the normal directory view
              doesn't use a standard look or format. When used like  this,  the  option
              causes a NLST command to be sent to the server instead of LIST.

              Note: Some FTP servers list only files in their response to NLST; they do
              not include sub-directories and symbolic links.

              (POP3) When retrieving a specific email from POP3, this switch  forces  a
              LIST command to be performed instead of RETR. This is particularly useful
              if the user wants to see if a specific message id exists  on  the  server
              and what size it is.

              Note:  When  combined with -X, --request, this option can be used to send
              an UIDL command instead, so the user may use the email's  unique  identi‐
              fier rather than it's message id to make the request.

              Added in 7.21.5.

       --local-port <num/range>
              Set a preferred single number or range (FROM-TO) of local port numbers to
              use for the connection(s).  Note that port numbers by nature are a scarce
              resource  that  will  be busy at times so setting this range to something
              too narrow might cause unnecessary connection setup failures.

              Added in 7.15.2.

       --location-trusted
              (HTTP) Like -L, --location, but will allow sending the name + password to
              all  hosts that the site may redirect to. This may or may not introduce a
              security breach if the site redirects you to a site to which you'll  send
              your  authentication  info  (which is plaintext in the case of HTTP Basic
              authentication).

              See also -u, --user.

       -L, --location
              (HTTP) If the server reports that the requested page has moved to a  dif‐
              ferent  location  (indicated  with  a Location: header and a 3XX response
              code), this option will make curl redo the request on the new  place.  If
              used  together  with  -i,  --include  or  -I,  --head,  headers  from all
              requested pages will be shown. When authentication  is  used,  curl  only
              sends  its credentials to the initial host. If a redirect takes curl to a
              different host, it won't be able to intercept the user+password. See also
              --location-trusted  on  how  to  change this. You can limit the amount of
              redirects to follow by using the --max-redirs option.

              When curl follows a redirect and the request is  not  a  plain  GET  (for
              example  POST or PUT), it will do the following request with a GET if the
              HTTP response was 301, 302, or 303. If the response code  was  any  other
              3xx  code, curl will re-send the following request using the same unmodi‐
              fied method.

              You can tell curl to not change the non-GET request method to GET after a
              30x  response  by  using  the  dedicated  options  for  that:  --post301,
              --post302 and --post303.

       --login-options <options>
              (IMAP POP3 SMTP) Specify the login options to use during server authenti‐
              cation.

              You  can  use the login options to specify protocol specific options that
              may be used during authentication. At present only IMAP,  POP3  and  SMTP
              support  login  options.  For  more  information  about the login options
              please  see  RFC  2384,  RFC  5092  and  IETF  draft   draft-earhart-url-
              smtp-00.txt

              If this option is used several times, the last one will be used.

              Added in 7.34.0.

       --mail-auth <address>
              (SMTP) Specify a single address. This will be used to specify the authen‐
              tication address (identity) of a submitted message that is being  relayed
              to another server.

              See also --mail-rcpt and --mail-from. Added in 7.25.0.

       --mail-from <address>
              (SMTP) Specify a single address that the given mail should get sent from.

              See also --mail-rcpt and --mail-auth. Added in 7.20.0.

       --mail-rcpt <address>
              (SMTP)  Specify  a single address, user name or mailing list name. Repeat
              this option several times to send to multiple recipients.

              When performing a mail transfer, the recipient  should  specify  a  valid
              email address to send the mail to.

              When  performing  an  address  verification (VRFY command), the recipient
              should be specified as the user name or user name and domain (as per Sec‐
              tion 3.5 of RFC5321). (Added in 7.34.0)

              When  performing  a  mailing  list  expand  (EXPN command), the recipient
              should be specified using the mailing list name,  such  as  "Friends"  or
              "London-Office".  (Added in 7.34.0)

              Added in 7.20.0.

       -M, --manual
              Manual. Display the huge help text.

       --max-filesize <bytes>
              Specify  the  maximum  size (in bytes) of a file to download. If the file
              requested is larger than this value, the transfer will not start and curl
              will return with exit code 63.

              NOTE:  The  file size is not always known prior to download, and for such
              files this option has no effect even if the file transfer ends  up  being
              larger than this given limit. This concerns both FTP and HTTP transfers.

              See also --limit-rate.

       --max-redirs <num>
              (HTTP)  Set  maximum  number  of redirection-followings allowed. When -L,
              --location is used, is used to prevent curl from  following  redirections
              "in  absurdum". By default, the limit is set to 50 redirections. Set this
              option to -1 to make it unlimited.

              If this option is used several times, the last one will be used.

       -m, --max-time <time>
              Maximum time in seconds that you allow the whole operation to take.  This
              is  useful  for  preventing your batch jobs from hanging for hours due to
              slow networks or links going down.  Since  7.32.0,  this  option  accepts
              decimal  values,  but the actual timeout will decrease in accuracy as the
              specified timeout increases in decimal precision.

              If this option is used several times, the last one will be used.

              See also --connect-timeout.

       --metalink
              This option can tell curl to parse and process a given  URI  as  Metalink
              file  (both version 3 and 4 (RFC 5854) are supported) and make use of the
              mirrors listed within for failover if there are errors (such as the  file
              or  server not being available). It will also verify the hash of the file
              after the download completes. The Metalink file itself is downloaded  and
              processed in memory and not stored in the local file system.

              Example to use a remote Metalink file:

               curl --metalink http://www.example.com/example.metalink

              To  use  a  Metalink  file  in  the  local file system, use FILE protocol
              (file://):

               curl --metalink file://example.metalink

              Please note that if FILE protocol is disabled, there is no way to  use  a
              local Metalink file at the time of this writing. Also note that if --met‐
              alink and -i, --include are used together,  --include  will  be  ignored.
              This  is  because  including  headers in the response will break Metalink
              parser and if the headers are included in the file described in  Metalink
              file, hash check will fail.

              --metalink requires that the underlying libcurl was built to support met‐
              alink. Added in 7.27.0.

       --negotiate
              (HTTP) Enables Negotiate (SPNEGO) authentication.

              This option requires a library built with GSS-API or  SSPI  support.  Use
              -V, --version to see if your curl supports GSS-API/SSPI or SPNEGO.

              When using this option, you must also provide a fake -u, --user option to
              activate the authentication code properly. Sending a '-u :' is enough  as
              the  user  name  and  password from the -u, --user option aren't actually
              used.

              If this option is used several times, only the first one is used.

              See also --basic and --ntlm and --anyauth and --proxy-negotiate.

       --netrc-file <filemame>
              This option is similar to -n, --netrc, except that you provide  the  path
              (absolute  or  relative) to the netrc file that Curl should use.  You can
              only specify one netrc  file  per  invocation.  If  several  --netrc-file
              options are provided, the last one will be used.

              It will abide by --netrc-optional if specified.

              This option overrides -n, --netrc. Added in 7.21.5.

       --netrc-optional
              Very  similar  to  -n,  --netrc,  but  this option makes the .netrc usage
              optional and not mandatory as the -n, --netrc option does.

              See also --netrc-file. This option overrides -n, --netrc.

       -n, --netrc
              Makes curl scan the .netrc (_netrc on Windows) file in  the  user's  home
              directory  for login name and password. This is typically used for FTP on
              Unix. If used with  HTTP,  curl  will  enable  user  authentication.  See
              netrc(5) ftp(1) for details on the file format. Curl will not complain if
              that file doesn't have the right permissions (it  should  not  be  either
              world-  or  group-readable).  The  environment variable "HOME" is used to
              find the home directory.

              A quick and very simple example of how to setup a .netrc to allow curl to
              FTP  to  the machine host.domain.com with user name 'myself' and password
              'secret' should look similar to:

              machine host.domain.com login myself password secret

       -:, --next
              Tells curl to use a separate operation for the following URL and  associ‐
              ated  options.  This  allows  you to send several URL requests, each with
              their own specific options, for example, such as different user names  or
              custom requests for each.

              -:,  --next  will  reset all local options and only global ones will have
              their values survive over to  the  operation  following  the  -:,  --next
              instruction. Global options include -v, --verbose and --fail-early.

              For example, you can do both a GET and a POST in a single command line:

               curl www1.example.com --next -d postthis www2.example.com

              Added in 7.36.0.

       --no-alpn
              (HTTPS)  Disable  the  ALPN  TLS extension. ALPN is enabled by default if
              libcurl was built with an SSL library that supports ALPN. ALPN is used by
              a  libcurl  that  supports  HTTP/2  to  negotiate HTTP/2 support with the
              server during https sessions.

              See also --no-npn and --http2. --no-alpn  requires  that  the  underlying
              libcurl was built to support TLS. Added in 7.36.0.

       -N, --no-buffer
              Disables  the  buffering of the output stream. In normal work situations,
              curl will use a standard buffered output stream that will have the effect
              that  it will output the data in chunks, not necessarily exactly when the
              data arrives.  Using this option will disable that buffering.

              Note that this is the negated option name documented. You  can  thus  use
              --buffer to enforce the buffering.

       --no-keepalive
              Disables the use of keepalive messages on the TCP connection. curl other‐
              wis enables them by default.

              Note that this is the negated option name documented. You  can  thus  use
              --keepalive to enforce keepalive.

       --no-npn
              (HTTPS)  Disable  the  NPN  TLS  extension.  NPN is enabled by default if
              libcurl was built with an SSL library that supports NPN. NPN is used by a
              libcurl  that supports HTTP/2 to negotiate HTTP/2 support with the server
              during https sessions.

              See also --no-alpn and --http2. --no-npn  requires  that  the  underlying
              libcurl was built to support TLS. Added in 7.36.0.

       --no-sessionid
              (TLS)  Disable  curl's  use  of  SSL  session-ID caching.  By default all
              transfers are done using the cache. Note that while nothing  should  ever
              get  hurt by attempting to reuse SSL session-IDs, there seem to be broken
              SSL implementations in the wild that may require you to disable  this  in
              order for you to succeed.

              Note  that  this  is the negated option name documented. You can thus use
              --sessionid to enforce session-ID caching.

              Added in 7.16.0.

       --noproxy <no-proxy-list>
              Comma-separated list of hosts which do not use a proxy, if one is  speci‐
              fied.   The  only  wildcard  is  a  single * character, which matches all
              hosts, and effectively disables the proxy. Each  name  in  this  list  is
              matched  as  either a domain which contains the hostname, or the hostname
              itself. For example, local.com would match local.com,  local.com:80,  and
              www.local.com, but not www.notlocal.com.

              Added in 7.19.4.

       --ntlm-wb
              (HTTP)  Enables  NTLM  much  in  the style --ntlm does, but hand over the
              authentication to the separate binary ntlmauth application that  is  exe‐
              cuted when needed.

              See also --ntlm and --proxy-ntlm.

       --ntlm (HTTP)  Enables  NTLM  authentication. The NTLM authentication method was
              designed by Microsoft and is used by IIS web servers. It is a proprietary
              protocol,  reverse-engineered  by  clever  people and implemented in curl
              based on their efforts. This kind of behavior should not be endorsed, you
              should  encourage  everyone who uses NTLM to switch to a public and docu‐
              mented authentication method instead, such as Digest.

              If you want to enable  NTLM  for  your  proxy  authentication,  then  use
              --proxy-ntlm.

              If this option is used several times, only the first one is used.

              See  also  --proxy-ntlm.  --ntlm requires that the underlying libcurl was
              built to support TLS. This option overrides --basic and --negotiated  and
              --digest and --anyauth.

       --oauth2-bearer
              (IMAP  POP3 SMTP) Specify the Bearer Token for OAUTH 2.0 server authenti‐
              cation. The Bearer Token is used in conjunction with the user name  which
              can be specified as part of the --url or -u, --user options.

              The Bearer Token and user name are formatted according to RFC 6750.

              If this option is used several times, the last one will be used.

       -o, --output <file>
              Write  output  to  <file> instead of stdout. If you are using {} or [] to
              fetch multiple documents, you can use '#' followed by  a  number  in  the
              <file>  specifier. That variable will be replaced with the current string
              for the URL being fetched. Like in:

               curl http://{one,two}.example.com -o "file_#1.txt"

              or use several variables like:

               curl http://{site,host}.host[1-5].com -o "#1_#2"

              You may use this option as many times as the number of URLs you have. For
              example, if you specify two URLs on the same command line, you can use it
              like this:

                curl -o aa example.com -o bb example.net

              and the order of the -o options and the URLs doesn't  matter,  just  that
              the  first  -o  is for the first URL and so on, so the above command line
              can also be written as

                curl example.com example.net -o aa -o bb

              See also the --create-dirs option to create the local directories dynami‐
              cally. Specifying the output as '-' (a single dash) will force the output
              to be done to stdout.

              See also -O, --remote-name and --remote-name-all and -J, --remote-header-
              name.

       --pass <phrase>
              (SSH TLS) Passphrase for the private key

              If this option is used several times, the last one will be used.

       --path-as-is
              Tell  curl  to not handle sequences of /../ or /./ in the given URL path.
              Normally curl will squash or merge them according to standards  but  with
              this option set you tell it not to do that.

              Added in 7.42.0.

       --pinnedpubkey <hashes>
              (TLS) Tells curl to use the specified public key file (or hashes) to ver‐
              ify the peer. This can be a path to a file which contains a single public
              key  in  PEM or DER format, or any number of base64 encoded sha256 hashes
              preceded by ´sha256//´ and separated by ´;´

              When negotiating a TLS or SSL connection, the server sends a  certificate
              indicating  its identity. A public key is extracted from this certificate
              and if it does not exactly match the public key provided to this  option,
              curl will abort the connection before sending or receiving any data.

              PEM/DER support:
                7.39.0: OpenSSL, GnuTLS and GSKit
                7.43.0: NSS and wolfSSL/CyaSSL
                7.47.0: mbedtls
                7.49.0: PolarSSL sha256 support:
                7.44.0: OpenSSL, GnuTLS, NSS and wolfSSL/CyaSSL.
                7.47.0: mbedtls
                7.49.0: PolarSSL Other SSL backends not supported.

              If this option is used several times, the last one will be used.

       --post301
              (HTTP) Tells curl to respect RFC 7231/6.4.2 and not convert POST requests
              into GET requests when following a 301 redirection. The non-RFC behaviour
              is  ubiquitous in web browsers, so curl does the conversion by default to
              maintain consistency. However, a server may require a POST  to  remain  a
              POST  after such a redirection. This option is meaningful only when using
              -L, --location.

              See also --post302 and --post303 and -L, --location. Added in 7.17.1.

       --post302
              (HTTP) Tells curl to respect RFC 7231/6.4.3 and not convert POST requests
              into GET requests when following a 302 redirection. The non-RFC behaviour
              is ubiquitous in web browsers, so curl does the conversion by default  to
              maintain  consistency.  However,  a server may require a POST to remain a
              POST after such a redirection. This option is meaningful only when  using
              -L, --location.

              See also --post301 and --post303 and -L, --location. Added in 7.19.1.

       --post303
              (HTTP) Tells curl to respect RFC 7231/6.4.4 and not convert POST requests
              into GET requests when following a 303 redirection. The non-RFC behaviour
              is  ubiquitous in web browsers, so curl does the conversion by default to
              maintain consistency. However, a server may require a POST  to  remain  a
              POST  after such a redirection. This option is meaningful only when using
              -L, --location.

              See also --post302 and --post301 and -L, --location. Added in 7.26.0.

       --preproxy [protocol://]host[:port]
              Use the specified proxy before connecting to the  ordinary  proxy.  Hence
              pre proxy. A pre proxy must be a SOCKS speaking proxy.

              The  pre  proxy  string  should be specified with a protocol:// prefix to
              specify alternative proxy protocols. Use socks4://, socks4a://, socks5://
              or socks5h:// to request the specific SOCKS version to be used. No proto‐
              col specified will make curl default to SOCKS4.

              If the port number is not specified in the proxy string, it is assumed to
              be 1080.

              User  and  password  that  might  be provided in the proxy string are URL
              decoded by curl. This allows you to pass in special characters such as  @
              by using %40 or pass in a colon with %3a.

              If this option is used several times, the last one will be used.

              Added in 7.52.0.

       -#, --progress-bar
              Make  curl  display transfer progress as a simple progress bar instead of
              the standard, more informational, meter.

              This progress bar draws a single line of '#' characters across the screen
              and shows a percentage if the transfer size is known. For transfers with‐
              out a known size, it will instead output one '#' character for every 1024
              bytes transferred.

       --proto-default <protocol>
              Tells curl to use protocol for any URL missing a scheme name.

              Example:

               curl --proto-default https ftp.mozilla.org

              An  unknown or unsupported protocol causes error CURLE_UNSUPPORTED_PROTO‐
              COL (1).

              This option does not change the default proxy protocol (http).

              Without this option curl would make a guess based on the host, see  --url
              for details.

              Added in 7.45.0.

       --proto-redir <protocols>
              Tells  curl  to  limit  what  protocols it may use on redirect. Protocols
              denied by --proto are not overridden by this option. See --proto for  how
              protocols are represented.

              Example, allow only HTTP and HTTPS on redirect:

               curl --proto-redir -all,http,https http://example.com

              By  default curl will allow all protocols on redirect except several dis‐
              abled for security reasons: Since 7.19.4 FILE and SCP are  disabled,  and
              since  7.40.0  SMB  and  SMBS  are  also disabled. Specifying all or +all
              enables all protocols on redirect, including those disabled for security.

              Added in 7.20.2.

       --proto <protocols>
              Tells curl to limit what protocols it may use in the transfer.  Protocols
              are evaluated left to right, are comma separated, and are each a protocol
              name or

              +  Permit this protocol in addition to protocols already permitted  (this
                 is the default if no modifier is used).

              -  Deny  this  protocol,  removing  it from the list of protocols already
                 permitted.

              =  Permit only this  protocol  (ignoring  the  list  already  permitted),
                 though  subject  to  later  modification  by subsequent entries in the
                 comma separated list.

              For example:

              --proto -ftps  uses the default protocols, but disables ftps

              --proto -all,https,+http
                             only enables http and https

              --proto =http,https
                             also only enables http and https

       Unknown protocols produce a warning. This allows scripts to safely rely on being
       able  to  disable  potentially dangerous protocols, without relying upon support
       for that protocol being built into curl to avoid an error.

       This option can be used multiple times, in which case the effect is the same  as
       concatenating the protocols into one instance of the option.

       See also --proto-redir and --proto-default. Added in 7.20.2.

       --proxy-anyauth
              Tells  curl  to  pick a suitable authentication method when communicating
              with the given HTTP proxy. This might  cause  an  extra  request/response
              round-trip.

              See  also  -x,  --proxy  and  --proxy-basic  and --proxy-digest. Added in
              7.13.2.

       --proxy-basic
              Tells curl to use HTTP Basic authentication when communicating  with  the
              given  proxy.  Use  --basic  for  enabling HTTP Basic with a remote host.
              Basic is the default authentication method curl uses with proxies.

              See also -x, --proxy and --proxy-anyauth and --proxy-digest.

       --proxy-cacert <file>
              Same as --cacert but used in HTTPS proxy context.

              See also --proxy-capath and --cacert and --capath and -x, --proxy.  Added
              in 7.52.0.

       --proxy-capath <dir>
              Same as --capath but used in HTTPS proxy context.

              See also --proxy-cacert and -x, --proxy and --capath. Added in 7.52.0.

       --proxy-cert-type <type>
              Same as --cert-type but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-cert <cert[:passwd]>
              Same as -E, --cert but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-ciphers <list>
              Same as --ciphers but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-crlfile <file>
              Same as --crlfile but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-digest
              Tells  curl to use HTTP Digest authentication when communicating with the
              given proxy. Use --digest for enabling HTTP Digest with a remote host.

              See also -x, --proxy and --proxy-anyauth and --proxy-basic.

       --proxy-header <header>
              (HTTP) Extra header to include in the request  when  sending  HTTP  to  a
              proxy.  You  may specify any number of extra headers. This is the equiva‐
              lent option to -H, --header but is for proxy communication only  like  in
              CONNECT  requests  when  you  want a separate header sent to the proxy to
              what is sent to the actual remote host.

              curl will make sure that each header you add/replace  is  sent  with  the
              proper  end-of-line marker, you should thus not add that as a part of the
              header content: do not add newlines or carriage returns, they  will  only
              mess things up for you.

              Headers  specified with this option will not be included in requests that
              curl knows will not be sent to a proxy.

              This option can be used multiple  times  to  add/replace/remove  multiple
              headers.

              Added in 7.37.0.

       --proxy-insecure
              Same as -k, --insecure but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-key-type <type>
              Same as --key-type but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-key <key>
              Same as --key but used in HTTPS proxy context.

       --proxy-negotiate
              Tells curl to use HTTP Negotiate (SPNEGO) authentication when communicat‐
              ing with the given proxy. Use --negotiate  for  enabling  HTTP  Negotiate
              (SPNEGO) with a remote host.

              See also --proxy-anyauth and --proxy-basic. Added in 7.17.1.

       --proxy-ntlm
              Tells  curl  to  use HTTP NTLM authentication when communicating with the
              given proxy. Use --ntlm for enabling NTLM with a remote host.

              See also --proxy-negotiate and --proxy-anyauth.

       --proxy-pass <phrase>
              Same as --pass but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-service-name <name>
              This option allows you to change the service name for proxy negotiation.

              Added in 7.43.0.

       --proxy-ssl-allow-beast
              Same as --ssl-allow-beast but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-tlsauthtype <type>
              Same as --tlsauthtype but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-tlspassword <string>
              Same as --tlspassword but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-tlsuser <name>
              Same as --tlsuser but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-tlsv1
              Same as -1, --tlsv1 but used in HTTPS proxy context.

              Added in 7.52.0.

       -U, --proxy-user <user:password>
              Specify the user name and password to use for proxy authentication.

              If you use a Windows SSPI-enabled curl binary and do either Negotiate  or
              NTLM  authentication  then  you can tell curl to select the user name and
              password from your environment by specifying a  single  colon  with  this
              option: "-U :".

              If this option is used several times, the last one will be used.

       -x, --proxy [protocol://]host[:port]
              Use the specified proxy.

              The  proxy  string  can be specified with a protocol:// prefix to specify
              alternative proxy protocols.  Use  socks4://,  socks4a://,  socks5://  or
              socks5h://  to request the specific SOCKS version to be used. No protocol
              specified, http:// and all others will be treated as HTTP  proxies.  (The
              protocol support was added in curl 7.21.7)

              If the port number is not specified in the proxy string, it is assumed to
              be 1080.

              This option overrides existing environment variables that set  the  proxy
              to  use.  If there's an environment variable setting a proxy, you can set
              proxy to "" to override it.

              All operations that are performed over an HTTP proxy  will  transparently
              be  converted to HTTP. It means that certain protocol specific operations
              might not be available. This is not the case if you  can  tunnel  through
              the proxy, as one with the -p, --proxytunnel option.

              User  and  password  that  might  be provided in the proxy string are URL
              decoded by curl. This allows you to pass in special characters such as  @
              by using %40 or pass in a colon with %3a.

              The  proxy host can be specified the exact same way as the proxy environ‐
              ment variables, including the protocol prefix (http://) and the  embedded
              user + password.

              If this option is used several times, the last one will be used.

       --proxy1.0 <host[:port]>
              Use the specified HTTP 1.0 proxy. If the port number is not specified, it
              is assumed at port 1080.

              The only difference between this and the HTTP proxy option  -x,  --proxy,
              is  that  attempts  to use CONNECT through the proxy will specify an HTTP
              1.0 protocol instead of the default HTTP 1.1.

       -p, --proxytunnel
              When an HTTP proxy is used -x, --proxy, this option will  cause  non-HTTP
              protocols  to attempt to tunnel through the proxy instead of merely using
              it to do HTTP-like operations. The tunnel approach is made with the  HTTP
              proxy  CONNECT  request and requires that the proxy allows direct connect
              to the remote port number curl wants to tunnel through to.

              See also -x, --proxy.

       --pubkey <key>
              (SFTP SCP) Public key file name. Allows you to provide your public key in
              this separate file.

              If this option is used several times, the last one will be used.

              (As of 7.39.0, curl attempts to automatically extract the public key from
              the private key file, so passing this option is generally  not  required.
              Note  that  this  public  key  extraction  requires  libcurl to be linked
              against a copy of libssh2 1.2.8 or higher that is itself  linked  against
              OpenSSL.)

       -Q, --quote
              (FTP  SFTP)  Send  an arbitrary command to the remote FTP or SFTP server.
              Quote commands are sent BEFORE the transfer takes place (just  after  the
              initial  PWD  command  in an FTP transfer, to be exact). To make commands
              take place after a successful transfer, prefix them with a dash '-'.   To
              make  commands be sent after curl has changed the working directory, just
              before the transfer command(s), prefix the command with a  '+'  (this  is
              only supported for FTP). You may specify any number of commands.

              If  the server returns failure for one of the commands, the entire opera‐
              tion will be aborted. You must send syntactically correct FTP commands as
              RFC  959  defines  to FTP servers, or one of the commands listed below to
              SFTP servers.

              This option can be used multiple times. When speaking to an  FTP  server,
              prefix the command with an asterisk (*) to make curl continue even if the
              command fails as by default curl will stop at first failure.

              SFTP is a binary protocol. Unlike for FTP,  curl  interprets  SFTP  quote
              commands  itself  before  sending  them to the server.  File names may be
              quoted shell-style to embed spaces or special characters.   Following  is
              the list of all supported SFTP quote commands:

              chgrp group file
                     The  chgrp command sets the group ID of the file named by the file
                     operand to the group ID specified by the group operand. The  group
                     operand is a decimal integer group ID.

              chmod mode file
                     The  chmod  command  modifies  the file mode bits of the specified
                     file. The mode operand is an octal integer mode number.

              chown user file
                     The chown command sets the owner of the file named by the file op‐
                     erand to the user ID specified by the user operand. The user oper‐
                     and is a decimal integer user ID.

              ln source_file target_file
                     The ln and symlink commands create a symbolic  link  at  the  tar‐
                     get_file location pointing to the source_file location.

              mkdir directory_name
                     The  mkdir  command  creates  the  directory  named  by the direc‐
                     tory_name operand.

              pwd    The pwd command returns the absolute pathname of the current work‐
                     ing directory.

              rename source target
                     The  rename  command  renames  the  file or directory named by the
                     source operand to the destination path named by the  target  oper‐
                     and.

              rm file
                     The rm command removes the file specified by the file operand.

              rmdir directory
                     The  rmdir  command  removes  the directory entry specified by the
                     directory operand, provided it is empty.

              symlink source_file target_file
                     See ln.

       --random-file <file>
              Specify the path name to file containing what will be considered as  ran‐
              dom  data. The data may be used to seed the random engine for SSL connec‐
              tions.  See also the --egd-file option.

       -r, --range <range>
              (HTTP FTP SFTP FILE) Retrieve a byte range (i.e a partial document)  from
              a  HTTP/1.1,  FTP or SFTP server or a local FILE. Ranges can be specified
              in a number of ways.

              0-499     specifies the first 500 bytes

              500-999   specifies the second 500 bytes

              -500      specifies the last 500 bytes

              9500-     specifies the bytes from offset 9500 and forward

              0-0,-1    specifies the first and last byte only(*)(HTTP)

              100-199,500-599
                        specifies two separate 100-byte ranges(*) (HTTP)

              (*) = NOTE that this will cause the server  to  reply  with  a  multipart
              response!

              Only digit characters (0-9) are valid in the 'start' and 'stop' fields of
              the 'start-stop' range syntax. If a non-digit character is given  in  the
              range,  the  server's  response  will  be  unspecified,  depending on the
              server's configuration.

              You should also be aware that many HTTP/1.1 servers do not have this fea‐
              ture enabled, so that when you attempt to get a range, you'll instead get
              the whole document.

              FTP and SFTP range downloads only support the simple 'start-stop'  syntax
              (optionally  with  one  of  the  numbers omitted). FTP use depends on the
              extended FTP command SIZE.

              If this option is used several times, the last one will be used.

       --raw  (HTTP) When used, it disables all internal HTTP decoding  of  content  or
              transfer encodings and instead makes them passed on unaltered, raw.

              Added in 7.16.2.

       -e, --referer <URL>
              (HTTP) Sends the "Referrer Page" information to the HTTP server. This can
              also be set with the -H, --header flag of course.   When  used  with  -L,
              --location  you  can append ";auto" to the -e, --referer URL to make curl
              automatically set the previous URL when it follows  a  Location:  header.
              The  ";auto"  string  can be used alone, even if you don't set an initial
              -e, --referer.

              If this option is used several times, the last one will be used.

              See also -A, --user-agent and -H, --header.

       -J, --remote-header-name
              (HTTP) This option tells the -O, --remote-name option to use the  server-
              specified  Content-Disposition  filename instead of extracting a filename
              from the URL.

              If the server specifies a file name and a file  with  that  name  already
              exists in the current working directory it will not be overwritten and an
              error will occur. If the server doesn't specify a  file  name  then  this
              option has no effect.

              There's no attempt to decode %-sequences (yet) in the provided file name,
              so this option may provide you with rather unexpected file names.

              WARNING: Exercise judicious use of this option, especially on Windows.  A
              rogue  server  could  send you the name of a DLL or other file that could
              possibly be loaded automatically by Windows or some third party software.

       --remote-name-all
              This option changes the default action for all given  URLs  to  be  dealt
              with  as  if  -O, --remote-name were used for each one. So if you want to
              disable that for a specific URL after --remote-name-all  has  been  used,
              you must use "-o -" or --no-remote-name.

              Added in 7.19.0.

       -O, --remote-name
              Write output to a local file named like the remote file we get. (Only the
              file part of the remote file is used, the path is cut off.)

              The file will be saved in the current working directory. If you want  the
              file  saved  in  a  different directory, make sure you change the current
              working directory before invoking curl with this option.

              The remote file name to use for saving is extracted from the  given  URL,
              nothing  else,  and  if  it already exists it will be overwritten. If you
              want the server to be able to choose the file name refer to -J, --remote-
              header-name  which  can be used in addition to this option. If the server
              chooses a file name and that name already exists it will not be overwrit‐
              ten.

              There  is  no  URL decoding done on the file name. If it has %20 or other
              URL encoded parts of the name, they will end up as-is as file name.

              You may use this option as many times as the number of URLs you have.

       -R, --remote-time
              When used, this will make curl attempt to figure out the timestamp of the
              remote  file,  and if that is available make the local file get that same
              timestamp.

       -X, --request <command>
              (HTTP) Specifies a custom request method to use when  communicating  with
              the  HTTP  server.   The specified request method will be used instead of
              the method otherwise used (which defaults to  GET).  Read  the  HTTP  1.1
              specification  for  details  and  explanations.  Common  additional  HTTP
              requests include PUT and DELETE, but  related  technologies  like  WebDAV
              offers PROPFIND, COPY, MOVE and more.

              Normally you don't need this option. All sorts of GET, HEAD, POST and PUT
              requests are rather invoked by using dedicated command line options.

              This option only changes the actual word used in  the  HTTP  request,  it
              does not alter the way curl behaves. So for example if you want to make a
              proper HEAD request, using -X HEAD will not suffice. You need to use  the
              -I, --head option.

              The  method  string  you  set  with  -X,  --request  will be used for all
              requests, which if you for example use -L,  --location  may  cause  unin‐
              tended  side-effects when curl doesn't change request method according to
              the HTTP 30x response codes - and similar.

              (FTP) Specifies a custom FTP command to use instead of  LIST  when  doing
              file lists with FTP.

              (POP3)  Specifies  a  custom POP3 command to use instead of LIST or RETR.
              (Added in 7.26.0)

              (IMAP) Specifies a custom IMAP command to use instead of LIST. (Added  in
              7.30.0)

              (SMTP)  Specifies  a  custom SMTP command to use instead of HELP or VRFY.
              (Added in 7.34.0)

              If this option is used several times, the last one will be used.

       --resolve <host:port:address>
              Provide a custom address for a specific host and port pair.  Using  this,
              you can make the curl requests(s) use a specified address and prevent the
              otherwise normally resolved address to be used. Consider  it  a  sort  of
              /etc/hosts  alternative  provided  on  the  command line. The port number
              should be the number used for the specific protocol the host will be used
              for. It means you need several entries if you want to provide address for
              the same host but different ports.

              The provided address set by this option will be used even if  -4,  --ipv4
              or -6, --ipv6 is set to make curl use another IP version.

              This option can be used many times to add many host names to resolve.

              Added in 7.21.3.

       --retry-connrefused
              In addition to the other conditions, consider ECONNREFUSED as a transient
              error too for --retry. This option is used together with --retry.

              Added in 7.52.0.

       --retry-delay <seconds>
              Make curl sleep this amount of time before each retry when a transfer has
              failed  with a transient error (it changes the default backoff time algo‐
              rithm between retries). This option is only  interesting  if  --retry  is
              also  used.  Setting  this  delay  to zero will make curl use the default
              backoff time.

              If this option is used several times, the last one will be used.

              Added in 7.12.3.

       --retry-max-time <seconds>
              The retry timer is reset before the first transfer attempt. Retries  will
              be  done  as usual (see --retry) as long as the timer hasn't reached this
              given limit. Notice that if the  timer  hasn't  reached  the  limit,  the
              request  will  be made and while performing, it may take longer than this
              given time period. To limit a single  request´s  maximum  time,  use  -m,
              --max-time.  Set this option to zero to not timeout retries.

              If this option is used several times, the last one will be used.

              Added in 7.12.3.

       --retry <num>
              If  a  transient error is returned when curl tries to perform a transfer,
              it will retry this number of times before giving up. Setting  the  number
              to  0  makes  curl  do no retries (which is the default). Transient error
              means either: a timeout, an FTP 4xx response code or an HTTP 5xx response
              code.

              When curl is about to retry a transfer, it will first wait one second and
              then for all forthcoming retries it will double the waiting time until it
              reaches  10  minutes which then will be the delay between the rest of the
              retries.  By using --retry-delay you  disable  this  exponential  backoff
              algorithm.  See also --retry-max-time to limit the total time allowed for
              retries.

              If this option is used several times, the last one will be used.

              Added in 7.12.3.

       --sasl-ir
              Enable initial response in SASL authentication.

              Added in 7.31.0.

       --service-name <name>
              This option allows you to change the service name for SPNEGO.

              Examples: --negotiate --service-name sockd would use sockd/server-name.

              Added in 7.43.0.

       -S, --show-error
              When used with -s, --silent, it makes curl show an error  message  if  it
              fails.

       -s, --silent
              Silent or quiet mode. Don't show progress meter or error messages.  Makes
              Curl mute. It will still output the data you ask for, potentially even to
              the terminal/stdout unless you redirect it.

              See also -v, --verbose and --stderr.

       --socks4 <host[:port]>
              Use  the  specified SOCKS4 proxy. If the port number is not specified, it
              is assumed at port 1080.

              This option overrides any previous use of -x, --proxy, as they are  mutu‐
              ally exclusive.

              Since  7.21.7,  this option is superfluous since you can specify a socks4
              proxy with -x, --proxy using a socks4:// protocol prefix.

              If this option is used several times, the last one will be used.

              Added in 7.15.2.

       --socks4a <host[:port]>
              Use the specified SOCKS4a proxy. If the port number is not specified,  it
              is assumed at port 1080.

              This  option overrides any previous use of -x, --proxy, as they are mutu‐
              ally exclusive.

              Since 7.21.7, this option is superfluous since you can specify a  socks4a
              proxy with -x, --proxy using a socks4a:// protocol prefix.

              If this option is used several times, the last one will be used.

              Added in 7.18.0.

       --socks5-gssapi-nec
              As  part  of the GSS-API negotiation a protection mode is negotiated. RFC
              1961 says in section 4.3/4.4 it should be protected, but the  NEC  refer‐
              ence  implementation does not.  The option --socks5-gssapi-nec allows the
              unprotected exchange of the protection mode negotiation.

              Added in 7.19.4.

       --socks5-gssapi-service <name>
              The default service name for a socks  server  is  rcmd/server-fqdn.  This
              option allows you to change it.

              Examples:  --socks5  proxy-name  --socks5-gssapi-service  sockd would use
              sockd/proxy-name --socks5 proxy-name --socks5-gssapi-service  sockd/real-
              name  would  use  sockd/real-name for cases where the proxy-name does not
              match the principal name.

              Added in 7.19.4.

       --socks5-hostname <host[:port]>
              Use the specified SOCKS5 proxy (and let the proxy resolve the host name).
              If the port number is not specified, it is assumed at port 1080.

              This  option overrides any previous use of -x, --proxy, as they are mutu‐
              ally exclusive.

              Since 7.21.7, this option is superfluous since you can specify  a  socks5
              hostname proxy with -x, --proxy using a socks5h:// protocol prefix.

              If this option is used several times, the last one will be used.

              Added in 7.18.0.

       --socks5 <host[:port]>
              Use  the  specified  SOCKS5 proxy - but resolve the host name locally. If
              the port number is not specified, it is assumed at port 1080.

              This option overrides any previous use of -x, --proxy, as they are  mutu‐
              ally exclusive.

              Since  7.21.7,  this option is superfluous since you can specify a socks5
              proxy with -x, --proxy using a socks5:// protocol prefix.

              If this option is used several times, the last one will be used.

              This option (as well as --socks4) does not work with IPV6, FTPS or LDAP.

              Added in 7.18.0.

       -Y, --speed-limit <speed>
              If a download is slower than this given speed (in bytes per  second)  for
              speed-time  seconds  it gets aborted. speed-time is set with -y, --speed-
              time and is 30 if not set.

              If this option is used several times, the last one will be used.

       -y, --speed-time <seconds>
              If a download is slower than speed-limit bytes per second during a speed-
              time  period,  the  download  gets  aborted.  If  speed-time is used, the
              default speed-limit will be 1 unless set with -Y, --speed-limit.

              This option controls transfers and thus will  not  affect  slow  connects
              etc. If this is a concern for you, try the --connect-timeout option.

              If this option is used several times, the last one will be used.

       --ssl-allow-beast
              This option tells curl to not work around a security flaw in the SSL3 and
              TLS1.0 protocols known as BEAST.  If this  option  isn't  used,  the  SSL
              layer  may  use workarounds known to cause interoperability problems with
              some older SSL implementations. WARNING:  this  option  loosens  the  SSL
              security, and by using this flag you ask for exactly that.

              Added in 7.25.0.

       --ssl-no-revoke
              (WinSSL) This option tells curl to disable certificate revocation checks.
              WARNING: this option loosens the SSL security, and by using this flag you
              ask for exactly that.

              Added in 7.44.0.

       --ssl-reqd
              (FTP  IMAP POP3 SMTP) Require SSL/TLS for the connection.  Terminates the
              connection if the server doesn't support SSL/TLS.

              This option was formerly known as --ftp-ssl-reqd.

              Added in 7.20.0.

       --ssl  (FTP IMAP POP3 SMTP) Try to use SSL/TLS for the connection.  Reverts to a
              non-secure  connection  if  the server doesn't support SSL/TLS.  See also
              --ftp-ssl-control and  --ssl-reqd  for  different  levels  of  encryption
              required.

              This  option  was  formerly  known  as  --ftp-ssl (Added in 7.11.0). That
              option name can still be used but will be removed in a future version.

              Added in 7.20.0.

       -2, --sslv2
              (SSL) Forces curl to use SSL version 2 when negotiating with a remote SSL
              server.  Sometimes  curl  is built without SSLv2 support. SSLv2 is widely
              considered insecure (see RFC 6176).

              See also --http1.1 and --http2. -2, --sslv2 requires that the  underlying
              libcurl  was  built to support TLS. This option overrides -3, --sslv3 and
              -1, --tlsv1 and --tlsv1.1 and --tlsv1.2.

       -3, --sslv3
              (SSL) Forces curl to use SSL version 3 when negotiating with a remote SSL
              server.  Sometimes  curl  is built without SSLv3 support. SSLv3 is widely
              considered insecure (see RFC 7568).

              See also --http1.1 and --http2. -3, --sslv3 requires that the  underlying
              libcurl  was  built to support TLS. This option overrides -2, --sslv2 and
              -1, --tlsv1 and --tlsv1.1 and --tlsv1.2.

       --stderr
              Redirect all writes to stderr to the specified file instead. If the  file
              name is a plain '-', it is instead written to stdout.

              If this option is used several times, the last one will be used.

              See also -v, --verbose and -s, --silent.

       --tcp-fastopen
              Enable use of TCP Fast Open (RFC7413).

              Added in 7.49.0.

       --tcp-nodelay
              Turn  on the TCP_NODELAY option. See the curl_easy_setopt(3) man page for
              details about this option.

              Since 7.50.2, curl sets this option by default and you need to  explicti‐
              tly switch it off if you don't want it on.

              Added in 7.11.2.

       -t, --telnet-option <opt=val>
              Pass options to the telnet protocol. Supported options are:

              TTYPE=<term> Sets the terminal type.

              XDISPLOC=<X display> Sets the X display location.

              NEW_ENV=<var,val> Sets an environment variable.

       --tftp-blksize <value>
              (TFTP)  Set  TFTP  BLKSIZE  option (must be >512). This is the block size
              that curl will try to use when  transferring  data  to  or  from  a  TFTP
              server. By default 512 bytes will be used.

              If this option is used several times, the last one will be used.

              Added in 7.20.0.

       --tftp-no-options
              (TFTP) Tells curl not to send TFTP options requests.

              This  option  improves  interop  with  some  legacy  servers  that do not
              acknowledge or properly implement TFTP options. When this option is  used
              --tftp-blksize is ignored.

              Added in 7.48.0.

       -z, --time-cond <time>
              (HTTP  FTP)  Request  a  file that has been modified later than the given
              time and date, or one that has been modified before that time. The  <date
              expression>  can  be all sorts of date strings or if it doesn't match any
              internal ones, it is taken as a filename and tries to get  the  modifica‐
              tion  date (mtime) from <file> instead. See the curl_getdate(3) man pages
              for date expression details.

              Start the date expression with a dash (-) to make it request for a  docu‐
              ment  that  is older than the given date/time, default is a document that
              is newer than the specified date/time.

              If this option is used several times, the last one will be used.

       --tlsauthtype <type>
              Set TLS authentication type. Currently,  the  only  supported  option  is
              "SRP",  for TLS-SRP (RFC 5054). If --tlsuser and --tlspassword are speci‐
              fied but --tlsauthtype is not, then this option defaults to "SRP".

              Added in 7.21.4.

       --tlspassword
              Set password for use with the TLS authentication  method  specified  with
              --tlsauthtype. Requires that --tlsuser also be set.

              Added in 7.21.4.

       --tlsuser <name>
              Set  username  for  use with the TLS authentication method specified with
              --tlsauthtype. Requires that --tlspassword also is set.

              Added in 7.21.4.

       --tlsv1.0
              (TLS) Forces curl to use TLS version 1.0 when connecting to a remote  TLS
              server.

              Added in 7.34.0.

       --tlsv1.1
              (TLS)  Forces curl to use TLS version 1.1 when connecting to a remote TLS
              server.

              Added in 7.34.0.

       --tlsv1.2
              (TLS) Forces curl to use TLS version 1.2 when connecting to a remote  TLS
              server.

              Added in 7.34.0.

       --tlsv1.3
              (TLS)  Forces curl to use TLS version 1.3 when connecting to a remote TLS
              server.

              Note that TLS 1.3 is only supported by a subset of TLS backends.  At  the
              time of writing this, those are BoringSSL and NSS only.

              Added in 7.52.0.

       -1, --tlsv1
              (SSL)  Tells  curl  to use TLS version 1.x when negotiating with a remote
              TLS server. That means TLS version 1.0, 1.1 or 1.2.

              See also --http1.1 and --http2. -1, --tlsv1 requires that the  underlying
              libcurl  was  built  to  support TLS. This option overrides --tlsv1.1 and
              --tlsv1.2 and --tlsv1.3.

       --tr-encoding
              (HTTP) Request a compressed Transfer-Encoding response using one  of  the
              algorithms curl supports, and uncompress the data while receiving it.

              Added in 7.21.6.

       --trace-ascii <file>
              Enables  a  full  trace dump of all incoming and outgoing data, including
              descriptive information, to the given output file. Use "-" as filename to
              have the output sent to stdout.

              This  is  very  similar  to --trace, but leaves out the hex part and only
              shows the ASCII part of the dump. It makes smaller output that  might  be
              easier to read for untrained humans.

              If this option is used several times, the last one will be used.

              This option overrides --trace and -v, --verbose.

       --trace-time
              Prepends a time stamp to each trace or verbose line that curl displays.

              Added in 7.14.0.

       --trace <file>
              Enables  a  full  trace dump of all incoming and outgoing data, including
              descriptive information, to the given output file. Use "-" as filename to
              have  the  output  sent to stdout. Use "%" as filename to have the output
              sent to stderr.

              If this option is used several times, the last one will be used.

              This option overrides -v, --verbose and --trace-ascii.

       --unix-socket <path>
              (HTTP) Connect through this Unix domain socket, instead of using the net‐
              work.

              Added in 7.40.0.

       -T, --upload-file <file>
              This transfers the specified local file to the remote URL. If there is no
              file part in the specified URL, curl will append  the  local  file  name.
              NOTE that you must use a trailing / on the last directory to really prove
              to Curl that there is no file name or curl  will  think  that  your  last
              directory  name  is  the  remote  file name to use. That will most likely
              cause the upload operation to fail. If this is used on an HTTP(S) server,
              the PUT command will be used.

              Use  the  file  name  "-" (a single dash) to use stdin instead of a given
              file.  Alternately, the file name "." (a single period) may be  specified
              instead  of "-" to use stdin in non-blocking mode to allow reading server
              output while stdin is being uploaded.

              You can specify one -T, --upload-file for each URL on the  command  line.
              Each  -T, --upload-file + URL pair specifies what to upload and to where.
              curl also supports "globbing" of the -T, --upload-file argument,  meaning
              that  you can upload multiple files to a single URL by using the same URL
              globbing style supported in the URL, like this:

               curl --upload-file "{file1,file2}" http://www.example.com

              or even

               curl -T "img[1-1000].png" ftp://ftp.example.com/upload/

              When uploading to an SMTP server: the uploaded data is assumed to be  RFC
              5322  formatted.  It has to feature the necessary set of headers and mail
              body formatted correctly by the user  as  curl  will  not  transcode  nor
              encode it further in any way.

       --url <url>
              Specify  a  URL  to  fetch.  This option is mostly handy when you want to
              specify URL(s) in a config file.

              If the given URL is missing a scheme name (such as "http://" or  "ftp://"
              etc) then curl will make a guess based on the host. If the outermost sub-
              domain name matches DICT, FTP, IMAP, LDAP, POP3 or SMTP then that  proto‐
              col  will be used, otherwise HTTP will be used. Since 7.45.0 guessing can
              be disabled by  setting  a  default  protocol,  see  --proto-default  for
              details.

              This option may be used any number of times. To control where this URL is
              written, use the -o, --output or the -O, --remote-name options.

       -B, --use-ascii
              (FTP LDAP) Enable ASCII transfer. For FTP, this can also be  enforced  by
              using  an  URL  that ends with ";type=A". This option causes data sent to
              stdout to be in text mode for win32 systems.

       -A, --user-agent <name>
              (HTTP) Specify the User-Agent string to  send  to  the  HTTP  server.  To
              encode blanks in the string, surround the string with single quote marks.
              This can also be set with the -H, --header option of course.

              If this option is used several times, the last one will be used.

       -u, --user <user:password>
              Specify the user name and password  to  use  for  server  authentication.
              Overrides -n, --netrc and --netrc-optional.

              If you simply specify the user name, curl will prompt for a password.

              The  user name and passwords are split up on the first colon, which makes
              it impossible to use a colon in the user name with this option. The pass‐
              word can, still.

              When using Kerberos V5 with a Windows based server you should include the
              Windows domain name in the user name, in order for the server to success‐
              fully obtain a Kerberos Ticket. If you don't then the initial authentica‐
              tion handshake may fail.

              When using NTLM, the user name can be specified simply as the user  name,
              without  the domain, if there is a single domain and forest in your setup
              for example.

              To specify the domain name use either Down-Level Logon Name or UPN  (User
              Principal  Name)  formats. For example, EXAMPLE\user and user@example.com
              respectively.

              If you use a Windows SSPI-enabled curl binary and  perform  Kerberos  V5,
              Negotiate, NTLM or Digest authentication then you can tell curl to select
              the user name and password from your environment by specifying  a  single
              colon with this option: "-u :".

              If this option is used several times, the last one will be used.

       -v, --verbose
              Makes  curl verbose during the operation. Useful for debugging and seeing
              what's going on "under the hood". A line starting with '>' means  "header
              data" sent by curl, '<' means "header data" received by curl that is hid‐
              den in normal cases, and a line starting with '*' means  additional  info
              provided by curl.

              If  you  only want HTTP headers in the output, -i, --include might be the
              option you're looking for.

              If you think this option still doesn't give you enough details,  consider
              using --trace or --trace-ascii instead.

              Use -s, --silent to make curl really quiet.

              See also -i, --include. This option overrides --trace and --trace-ascii.

       -V, --version
              Displays information about curl and the libcurl version it uses.

              The  first  line includes the full version of curl, libcurl and other 3rd
              party libraries linked with the executable.

              The second line (starts  with  "Protocols:")  shows  all  protocols  that
              libcurl reports to support.

              The  third line (starts with "Features:") shows specific features libcurl
              reports to offer. Available features include:

              IPv6   You can use IPv6 with this.

              krb4   Krb4 for FTP is supported.

              SSL    SSL versions of various protocols are supported,  such  as  HTTPS,
                     FTPS, POP3S and so on.

              libz   Automatic  decompression  of  compressed  files  over HTTP is sup‐
                     ported.

              NTLM   NTLM authentication is supported.

              Debug  This curl uses a libcurl  built  with  Debug.  This  enables  more
                     error-tracking and memory debugging etc. For curl-developers only!

              AsynchDNS
                     This  curl  uses  asynchronous  name  resolves.  Asynchronous name
                     resolves can be done using  either  the  c-ares  or  the  threaded
                     resolver backends.

              SPNEGO SPNEGO authentication is supported.

              Largefile
                     This  curl  supports  transfers  of large files, files larger than
                     2GB.

              IDN    This curl supports IDN - international domain names.

              GSS-API
                     GSS-API is supported.

              SSPI   SSPI is supported.

              TLS-SRP
                     SRP (Secure Remote Password) authentication is supported for TLS.

              HTTP2  HTTP/2 support has been built-in.

              UnixSockets
                     Unix sockets support is provided.

              HTTPS-proxy
                     This curl is built to support HTTPS proxy.

              Metalink
                     This curl supports Metalink (both version 3  and  4  (RFC  5854)),
                     which  describes  mirrors  and  hashes.  curl will use mirrors for
                     failover if there are errors (such as the file or server not being
                     available).

              PSL    PSL  is  short for Public Suffix List and means that this curl has
                     been built with knowledge about "public suffixes".

       -w, --write-out <format>
              Make curl display information on stdout after a completed  transfer.  The
              format  is  a string that may contain plain text mixed with any number of
              variables. The format can be specified as a literal "string", or you  can
              have  curl  read the format from a file with "@filename" and to tell curl
              to read the format from stdin you write "@-".

              The variables present in the output format will  be  substituted  by  the
              value or text that curl thinks fit, as described below. All variables are
              specified as %{variable_name} and to output a normal  %  you  just  write
              them  as %%. You can output a newline by using \n, a carriage return with
              \r and a tab space with \t.

              NOTE: The %-symbol is a special symbol in  the  win32-environment,  where
              all occurrences of % must be doubled when using this option.

              The variables available are:

              content_type   The  Content-Type  of the requested document, if there was
                             any.

              filename_effective
                             The ultimate filename that curl writes  out  to.  This  is
                             only  meaningful  if  curl is told to write to a file with
                             the -O, --remote-name or -o, --output  option.  It's  most
                             useful  in  combination  with the -J, --remote-header-name
                             option. (Added in 7.26.0)

              ftp_entry_path The initial path curl ended up in when logging on  to  the
                             remote FTP server. (Added in 7.15.4)

              http_code      The  numerical  response  code  that was found in the last
                             retrieved HTTP(S) or FTP(s) transfer. In 7.18.2 the  alias
                             response_code was added to show the same info.

              http_connect   The  numerical  code  that  was found in the last response
                             (from a proxy)  to  a  curl  CONNECT  request.  (Added  in
                             7.12.4)

              http_version   The  http  version  that  was  effectively used. (Added in
                             7.50.0)

              local_ip       The IP address of the local end of the most recently  done
                             connection - can be either IPv4 or IPv6 (Added in 7.29.0)

              local_port     The local port number of the most recently done connection
                             (Added in 7.29.0)

              num_connects   Number of new connects made in the recent transfer. (Added
                             in 7.12.3)

              num_redirects  Number  of  redirects  that  were followed in the request.
                             (Added in 7.12.3)

              redirect_url   When an HTTP request was made without -L to  follow  redi‐
                             rects,  this  variable will show the actual URL a redirect
                             would take you to. (Added in 7.18.2)

              remote_ip      The remote IP address of the most recently done connection
                             - can be either IPv4 or IPv6 (Added in 7.29.0)

              remote_port    The  remote  port number of the most recently done connec‐
                             tion (Added in 7.29.0)

              scheme         The URL scheme (sometimes called protocol) that was effec‐
                             tively used (Added in 7.52.0)

              size_download  The total amount of bytes that were downloaded.

              size_header    The total amount of bytes of the downloaded headers.

              size_request   The  total  amount  of  bytes  that  were sent in the HTTP
                             request.

              size_upload    The total amount of bytes that were uploaded.

              speed_download The average download speed that curl measured for the com‐
                             plete download. Bytes per second.

              speed_upload   The  average  upload speed that curl measured for the com‐
                             plete upload. Bytes per second.

              ssl_verify_result
                             The result of the SSL peer certificate  verification  that
                             was  requested.  0  means the verification was successful.
                             (Added in 7.19.0)

              time_appconnect
                             The time, in seconds, it took from  the  start  until  the
                             SSL/SSH/etc  connect/handshake to the remote host was com‐
                             pleted. (Added in 7.19.0)

              time_connect   The time, in seconds, it took from the start until the TCP
                             connect to the remote host (or proxy) was completed.

              time_namelookup
                             The  time,  in  seconds,  it took from the start until the
                             name resolving was completed.

              time_pretransfer
                             The time, in seconds, it took from  the  start  until  the
                             file  transfer  was just about to begin. This includes all
                             pre-transfer commands and negotiations that  are  specific
                             to the particular protocol(s) involved.

              time_redirect  The  time,  in  seconds, it took for all redirection steps
                             include name lookup,  connect,  pretransfer  and  transfer
                             before  the  final  transaction was started. time_redirect
                             shows the complete execution time  for  multiple  redirec‐
                             tions. (Added in 7.12.3)

              time_starttransfer
                             The  time,  in  seconds,  it took from the start until the
                             first byte was just about to be transferred. This includes
                             time_pretransfer  and  also  the time the server needed to
                             calculate the result.

              time_total     The total  time,  in  seconds,  that  the  full  operation
                             lasted.  The time will be displayed with millisecond reso‐
                             lution.

              url_effective  The URL that was fetched last. This is most meaningful  if
                             you've told curl to follow location: headers.

              If this option is used several times, the last one will be used.

       --xattr
              When  saving  output  to  a file, this option tells curl to store certain
              file metadata in extended file attributes. Currently, the URL  is  stored
              in the xdg.origin.url attribute and, for HTTP, the content type is stored
              in the mime_type attribute. If the file system does not support  extended
              attributes, a warning is issued.

FILES
       ~/.curlrc
              Default config file, see -K, --config for details.

ENVIRONMENT
       The  environment  variables  can  be  specified in lower case or upper case. The
       lower case version has precedence. http_proxy is an  exception  as  it  is  only
       available in lower case.

       Using  an environment variable to set the proxy has the same effect as using the
       -x, --proxy option.

       http_proxy [protocol://]<host>[:port]
              Sets the proxy server to use for HTTP.

       HTTPS_PROXY [protocol://]<host>[:port]
              Sets the proxy server to use for HTTPS.

       [url-protocol]_PROXY [protocol://]<host>[:port]
              Sets the proxy server to use for [url-protocol], where the protocol is  a
              protocol  that  curl supports and as specified in a URL. FTP, FTPS, POP3,
              IMAP, SMTP, LDAP etc.

       ALL_PROXY [protocol://]<host>[:port]
              Sets the proxy server to use if no protocol-specific proxy is set.

       NO_PROXY <comma-separated list of hosts>
              list of host names that shouldn't go through  any  proxy.  If  set  to  a
              asterisk '*' only, it matches all hosts.

PROXY PROTOCOL PREFIXES
       Since  curl version 7.21.7, the proxy string may be specified with a protocol://
       prefix to specify alternative proxy protocols.

       If no protocol is specified in the proxy string or if the string doesn't match a
       supported one, the proxy will be treated as an HTTP proxy.

       The supported proxy protocol prefixes are as follows:

       socks4://
              Makes it the equivalent of --socks4

       socks4a://
              Makes it the equivalent of --socks4a

       socks5://
              Makes it the equivalent of --socks5

       socks5h://
              Makes it the equivalent of --socks5-hostname

EXIT CODES
       There  are  a  bunch of different error codes and their corresponding error mes‐
       sages that may appear during bad conditions. At the time of  this  writing,  the
       exit codes are:

       1      Unsupported  protocol.  This build of curl has no support for this proto‐
              col.

       2      Failed to initialize.

       3      URL malformed. The syntax was not correct.

       4      A feature or option that was needed to perform the  desired  request  was
              not  enabled  or was explicitly disabled at build-time. To make curl able
              to do this, you probably need another build of libcurl!

       5      Couldn't resolve proxy. The given proxy host could not be resolved.

       6      Couldn't resolve host. The given remote host was not resolved.

       7      Failed to connect to host.

       8      Weird server reply. The server sent data curl couldn't parse.

       9      FTP access denied. The server denied login or denied access to  the  par‐
              ticular  resource  or directory you wanted to reach. Most often you tried
              to change to a directory that doesn't exist on the server.

       11     FTP weird PASS reply. Curl couldn't parse the  reply  sent  to  the  PASS
              request.

       13     FTP  weird  PASV  reply,  Curl  couldn't parse the reply sent to the PASV
              request.

       14     FTP weird 227 format. Curl couldn't parse the 227-line the server sent.

       15     FTP can't get host. Couldn't resolve the host IP we got in the 227-line.

       17     FTP couldn't set binary. Couldn't change transfer method to binary.

       18     Partial file. Only a part of the file was transferred.

       19     FTP couldn't download/access the given file, the RETR (or  similar)  com‐
              mand failed.

       21     FTP quote error. A quote command returned error from the server.

       22     HTTP  page  not  retrieved.  The  requested url was not found or returned
              another error with the HTTP error code being 400 or  above.  This  return
              code only appears if -f, --fail is used.

       23     Write error. Curl couldn't write data to a local filesystem or similar.

       25     FTP  couldn't  STOR  file. The server denied the STOR operation, used for
              FTP uploading.

       26     Read error. Various reading problems.

       27     Out of memory. A memory allocation request failed.

       28     Operation timeout. The specified time-out period was reached according to
              the conditions.

       30     FTP PORT failed. The PORT command failed. Not all FTP servers support the
              PORT command, try doing a transfer using PASV instead!

       31     FTP couldn't use REST. The REST command failed. This command is used  for
              resumed FTP transfers.

       33     HTTP range error. The range "command" didn't work.

       34     HTTP post error. Internal post-request generation error.

       35     SSL connect error. The SSL handshaking failed.

       36     FTP bad download resume. Couldn't continue an earlier aborted download.

       37     FILE couldn't read file. Failed to open the file. Permissions?

       38     LDAP cannot bind. LDAP bind operation failed.

       39     LDAP search failed.

       41     Function not found. A required LDAP function was not found.

       42     Aborted by callback. An application told curl to abort the operation.

       43     Internal error. A function was called with a bad parameter.

       45     Interface error. A specified outgoing interface could not be used.

       47     Too  many  redirects.  When  following  redirects,  curl  hit the maximum
              amount.

       48     Unknown option specified to libcurl. This indicates  that  you  passed  a
              weird  option to curl that was passed on to libcurl and rejected. Read up
              in the manual!

       49     Malformed telnet option.

       51     The peer's SSL certificate or SSH MD5 fingerprint was not OK.

       52     The server didn't reply anything, which here is considered an error.

       53     SSL crypto engine not found.

       54     Cannot set SSL crypto engine as default.

       55     Failed sending network data.

       56     Failure in receiving network data.

       58     Problem with the local certificate.

       59     Couldn't use specified SSL cipher.

       60     Peer certificate cannot be authenticated with known CA certificates.

       61     Unrecognized transfer encoding.

       62     Invalid LDAP URL.

       63     Maximum file size exceeded.

       64     Requested FTP SSL level failed.

       65     Sending the data requires a rewind that failed.

       66     Failed to initialise SSL Engine.

       67     The user name, password, or similar was not accepted and curl  failed  to
              log in.

       68     File not found on TFTP server.

       69     Permission problem on TFTP server.

       70     Out of disk space on TFTP server.

       71     Illegal TFTP operation.

       72     Unknown TFTP transfer ID.

       73     File already exists (TFTP).

       74     No such user (TFTP).

       75     Character conversion failed.

       76     Character conversion functions required.

       77     Problem with reading the SSL CA cert (path? access rights?).

       78     The resource referenced in the URL does not exist.

       79     An unspecified error occurred during the SSH session.

       80     Failed to shut down the SSL connection.

       82     Could not load CRL file, missing or wrong format (added in 7.19.0).

       83     Issuer check failed (added in 7.19.0).

       84     The FTP PRET command failed

       85     RTSP: mismatch of CSeq numbers

       86     RTSP: mismatch of Session Identifiers

       87     unable to parse FTP file list

       88     FTP chunk callback reported error

       89     No connection available, the session will be queued

       90     SSL public key does not matched pinned public key

       XX     More  error  codes will appear here in future releases. The existing ones
              are meant to never change.

AUTHORS / CONTRIBUTORS
       Daniel Stenberg is the main author, but the whole list of contributors is  found
       in the separate THANKS file.

WWW
       https://curl.haxx.se

FTP
       ftp://ftp.sunet.se/pub/www/utilities/curl/

SEE ALSO
       ftp(1), wget(1)

Curl 7.52.0                           16 Dec 2016                               curl(1)

 

 

Súgó kimenet

curl --help
Usage: curl [options...] <url>
Options: (H) means HTTP/HTTPS only, (F) means FTP only
     --anyauth       Pick "any" authentication method (H)
 -a, --append        Append to target file when uploading (F/SFTP)
     --basic         Use HTTP Basic Authentication (H)
     --cacert FILE   CA certificate to verify peer against (SSL)
     --capath DIR    CA directory to verify peer against (SSL)
 -E, --cert CERT[:PASSWD]  Client certificate file and password (SSL)
     --cert-status   Verify the status of the server certificate (SSL)
     --cert-type TYPE  Certificate file type (DER/PEM/ENG) (SSL)
     --ciphers LIST  SSL ciphers to use (SSL)
     --compressed    Request compressed response (using deflate or gzip)
 -K, --config FILE   Read config from FILE
     --connect-timeout SECONDS  Maximum time allowed for connection
     --connect-to HOST1:PORT1:HOST2:PORT2 Connect to host (network level)
 -C, --continue-at OFFSET  Resumed transfer OFFSET
 -b, --cookie STRING/FILE  Read cookies from STRING/FILE (H)
 -c, --cookie-jar FILE  Write cookies to FILE after operation (H)
     --create-dirs   Create necessary local directory hierarchy
     --crlf          Convert LF to CRLF in upload
     --crlfile FILE  Get a CRL list in PEM format from the given file
 -d, --data DATA     HTTP POST data (H)
     --data-raw DATA  HTTP POST data, '@' allowed (H)
     --data-ascii DATA  HTTP POST ASCII data (H)
     --data-binary DATA  HTTP POST binary data (H)
     --data-urlencode DATA  HTTP POST data url encoded (H)
     --delegation STRING  GSS-API delegation permission
     --digest        Use HTTP Digest Authentication (H)
     --disable-eprt  Inhibit using EPRT or LPRT (F)
     --disable-epsv  Inhibit using EPSV (F)
     --dns-servers   DNS server addrs to use: 1.1.1.1;2.2.2.2
     --dns-interface  Interface to use for DNS requests
     --dns-ipv4-addr  IPv4 address to use for DNS requests, dot notation
     --dns-ipv6-addr  IPv6 address to use for DNS requests, dot notation
 -D, --dump-header FILE  Write the received headers to FILE
     --egd-file FILE  EGD socket path for random data (SSL)
     --engine ENGINE  Crypto engine (use "--engine list" for list) (SSL)
     --expect100-timeout SECONDS How long to wait for 100-continue (H)
 -f, --fail          Fail silently (no output at all) on HTTP errors (H)
     --fail-early    Fail on first transfer error, do not continue
     --false-start   Enable TLS False Start.
 -F, --form CONTENT  Specify HTTP multipart POST data (H)
     --form-string STRING  Specify HTTP multipart POST data (H)
     --ftp-account DATA  Account data string (F)
     --ftp-alternative-to-user COMMAND  String to replace "USER [name]" (F)
     --ftp-create-dirs  Create the remote dirs if not present (F)
     --ftp-method [MULTICWD/NOCWD/SINGLECWD]  Control CWD usage (F)
     --ftp-pasv      Use PASV/EPSV instead of PORT (F)
 -P, --ftp-port ADR  Use PORT with given address instead of PASV (F)
     --ftp-skip-pasv-ip  Skip the IP address for PASV (F)
     --ftp-pret      Send PRET before PASV (for drftpd) (F)
     --ftp-ssl-ccc   Send CCC after authenticating (F)
     --ftp-ssl-ccc-mode ACTIVE/PASSIVE  Set CCC mode (F)
     --ftp-ssl-control  Require SSL/TLS for FTP login, clear for transfer (F)
 -G, --get           Send the -d data with a HTTP GET (H)
 -g, --globoff       Disable URL sequences and ranges using {} and []
 -H, --header LINE   Pass custom header LINE to server (H)
 -I, --head          Show document info only
 -h, --help          This help text
     --hostpubmd5 MD5  Hex-encoded MD5 string of the host public key. (SSH)
 -0, --http1.0       Use HTTP 1.0 (H)
     --http1.1       Use HTTP 1.1 (H)
     --http2         Use HTTP 2 (H)
     --http2-prior-knowledge  Use HTTP 2 without HTTP/1.1 Upgrade (H)
     --ignore-content-length  Ignore the HTTP Content-Length header
 -i, --include       Include protocol headers in the output (H/F)
 -k, --insecure      Allow connections to SSL sites without certs (H)
     --interface INTERFACE  Use network INTERFACE (or address)
 -4, --ipv4          Resolve name to IPv4 address
 -6, --ipv6          Resolve name to IPv6 address
 -j, --junk-session-cookies  Ignore session cookies read from file (H)
     --keepalive-time SECONDS  Wait SECONDS between keepalive probes
     --key KEY       Private key file name (SSL/SSH)
     --key-type TYPE  Private key file type (DER/PEM/ENG) (SSL)
     --krb LEVEL     Enable Kerberos with security LEVEL (F)
     --libcurl FILE  Dump libcurl equivalent code of this command line
     --limit-rate RATE  Limit transfer speed to RATE
 -l, --list-only     List only mode (F/POP3)
     --local-port RANGE  Force use of RANGE for local port numbers
 -L, --location      Follow redirects (H)
     --location-trusted  Like '--location', and send auth to other hosts (H)
     --login-options OPTIONS  Server login options (IMAP, POP3, SMTP)
 -M, --manual        Display the full manual
     --mail-from FROM  Mail from this address (SMTP)
     --mail-rcpt TO  Mail to this/these addresses (SMTP)
     --mail-auth AUTH  Originator address of the original email (SMTP)
     --max-filesize BYTES  Maximum file size to download (H/F)
     --max-redirs NUM  Maximum number of redirects allowed (H)
 -m, --max-time SECONDS  Maximum time allowed for the transfer
     --metalink      Process given URLs as metalink XML file
     --negotiate     Use HTTP Negotiate (SPNEGO) authentication (H)
 -n, --netrc         Must read .netrc for user name and password
     --netrc-optional  Use either .netrc or URL; overrides -n
     --netrc-file FILE  Specify FILE for netrc
 -:, --next          Allows the following URL to use a separate set of options
     --no-alpn       Disable the ALPN TLS extension (H)
 -N, --no-buffer     Disable buffering of the output stream
     --no-keepalive  Disable keepalive use on the connection
     --no-npn        Disable the NPN TLS extension (H)
     --no-sessionid  Disable SSL session-ID reusing (SSL)
     --noproxy       List of hosts which do not use proxy
     --ntlm          Use HTTP NTLM authentication (H)
     --ntlm-wb       Use HTTP NTLM authentication with winbind (H)
     --oauth2-bearer TOKEN  OAuth 2 Bearer Token (IMAP, POP3, SMTP)
 -o, --output FILE   Write to FILE instead of stdout
     --pass PASS     Pass phrase for the private key (SSL/SSH)
     --path-as-is    Do not squash .. sequences in URL path
     --pinnedpubkey FILE/HASHES Public key to verify peer against (SSL)
     --post301       Do not switch to GET after following a 301 redirect (H)
     --post302       Do not switch to GET after following a 302 redirect (H)
     --post303       Do not switch to GET after following a 303 redirect (H)
     --preproxy [PROTOCOL://]HOST[:PORT] Proxy before HTTP(S) proxy
 -#, --progress-bar  Display transfer progress as a progress bar
     --proto PROTOCOLS  Enable/disable PROTOCOLS
     --proto-default PROTOCOL  Use PROTOCOL for any URL missing a scheme
     --proto-redir PROTOCOLS   Enable/disable PROTOCOLS on redirect
 -x, --proxy [PROTOCOL://]HOST[:PORT]  Use proxy on given port
     --proxy-anyauth  Pick "any" proxy authentication method (H)
     --proxy-basic   Use Basic authentication on the proxy (H)
     --proxy-digest  Use Digest authentication on the proxy (H)
     --proxy-cacert FILE CA certificate to verify peer against for proxy (SSL)
     --proxy-capath DIR CA directory to verify peer against for proxy (SSL)
     --proxy-cert CERT[:PASSWD] Client certificate file and password for proxy (SSL)
     --proxy-cert-type TYPE Certificate file type (DER/PEM/ENG) for proxy (SSL)
     --proxy-ciphers LIST SSL ciphers to use for proxy (SSL)
     --proxy-crlfile FILE Get a CRL list in PEM format from the given file for proxy
     --proxy-insecure Allow connections to SSL sites without certs for proxy (H)
     --proxy-key KEY Private key file name for proxy (SSL)
     --proxy-key-type TYPE Private key file type for proxy (DER/PEM/ENG) (SSL)
     --proxy-negotiate  Use HTTP Negotiate (SPNEGO) authentication on the proxy (H)
     --proxy-ntlm    Use NTLM authentication on the proxy (H)
     --proxy-header LINE Pass custom header LINE to proxy (H)
     --proxy-pass PASS Pass phrase for the private key for proxy (SSL)
     --proxy-ssl-allow-beast Allow security flaw to improve interop for proxy (SSL)
     --proxy-tlsv1   Use TLSv1 for proxy (SSL)
     --proxy-tlsuser USER TLS username for proxy
     --proxy-tlspassword STRING TLS password for proxy
     --proxy-tlsauthtype STRING TLS authentication type for proxy (default SRP)
     --proxy-service-name NAME  SPNEGO proxy service name
     --service-name NAME  SPNEGO service name
 -U, --proxy-user USER[:PASSWORD]  Proxy user and password
     --proxy1.0 HOST[:PORT]  Use HTTP/1.0 proxy on given port
 -p, --proxytunnel   Operate through a HTTP proxy tunnel (using CONNECT)
     --pubkey KEY    Public key file name (SSH)
 -Q, --quote CMD     Send command(s) to server before transfer (F/SFTP)
     --random-file FILE  File for reading random data from (SSL)
 -r, --range RANGE   Retrieve only the bytes within RANGE
     --raw           Do HTTP "raw"; no transfer decoding (H)
 -e, --referer       Referer URL (H)
 -J, --remote-header-name  Use the header-provided filename (H)
 -O, --remote-name   Write output to a file named as the remote file
     --remote-name-all  Use the remote file name for all URLs
 -R, --remote-time   Set the remote file's time on the local output
 -X, --request COMMAND  Specify request command to use
     --resolve HOST:PORT:ADDRESS  Force resolve of HOST:PORT to ADDRESS
     --retry NUM   Retry request NUM times if transient problems occur
     --retry-connrefused  Retry on connection refused (use with --retry)
     --retry-delay SECONDS  Wait SECONDS between retries
     --retry-max-time SECONDS  Retry only within this period
     --sasl-ir       Enable initial response in SASL authentication
 -S, --show-error    Show error. With -s, make curl show errors when they occur
 -s, --silent        Silent mode (don't output anything)
     --socks4 HOST[:PORT]  SOCKS4 proxy on given host + port
     --socks4a HOST[:PORT]  SOCKS4a proxy on given host + port
     --socks5 HOST[:PORT]  SOCKS5 proxy on given host + port
     --socks5-hostname HOST[:PORT]  SOCKS5 proxy, pass host name to proxy
     --socks5-gssapi-service NAME  SOCKS5 proxy service name for GSS-API
     --socks5-gssapi-nec  Compatibility with NEC SOCKS5 server
 -Y, --speed-limit RATE  Stop transfers below RATE for 'speed-time' secs
 -y, --speed-time SECONDS  Trigger 'speed-limit' abort after SECONDS (default: 30)
     --ssl           Try SSL/TLS (FTP, IMAP, POP3, SMTP)
     --ssl-reqd      Require SSL/TLS (FTP, IMAP, POP3, SMTP)
 -2, --sslv2         Use SSLv2 (SSL)
 -3, --sslv3         Use SSLv3 (SSL)
     --ssl-allow-beast  Allow security flaw to improve interop (SSL)
     --ssl-no-revoke    Disable cert revocation checks (WinSSL)
     --stderr FILE   Where to redirect stderr (use "-" for stdout)
     --tcp-nodelay   Use the TCP_NODELAY option
     --tcp-fastopen  Use TCP Fast Open
 -t, --telnet-option OPT=VAL  Set telnet option
     --tftp-blksize VALUE  Set TFTP BLKSIZE option (must be >512)
     --tftp-no-options  Do not send TFTP options requests
 -z, --time-cond TIME   Transfer based on a time condition
 -1, --tlsv1         Use >= TLSv1 (SSL)
     --tlsv1.0       Use TLSv1.0 (SSL)
     --tlsv1.1       Use TLSv1.1 (SSL)
     --tlsv1.2       Use TLSv1.2 (SSL)
     --tlsv1.3       Use TLSv1.3 (SSL)
     --trace FILE    Write a debug trace to FILE
     --trace-ascii FILE  Like --trace, but without hex output
     --trace-time    Add time stamps to trace/verbose output
     --tr-encoding   Request compressed transfer encoding (H)
 -T, --upload-file FILE  Transfer FILE to destination
     --url URL       URL to work with
 -B, --use-ascii     Use ASCII/text transfer
 -u, --user USER[:PASSWORD]  Server user and password
     --tlsuser USER  TLS username
     --tlspassword STRING  TLS password
     --tlsauthtype STRING  TLS authentication type (default: SRP)
     --unix-socket FILE    Connect through this Unix domain socket
 -A, --user-agent STRING  Send User-Agent STRING to server (H)
 -v, --verbose       Make the operation more talkative
 -V, --version       Show version number and quit
 -w, --write-out FORMAT  Use output FORMAT after completion
     --xattr         Store metadata in extended file attributes
 -q, --disable       Disable .curlrc (must be first parameter)

 

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