read (beépített Bash parancs)

Tartalom

 

Adatok

Licenc: GNU GPLv3+
Verziószám: GNU Bash 5
Fejlesztő/tulajdonos: Free Software Foundation Inc.

Rövid leírás:

A read beépített Bash parancs manual oldala és súgója. A read parancs beolvas egy vagy több sort a szabványos bemenetről és a megadott változóba teszi.

 

 

Man oldal kimenet

man read
[...]
       read  [-ers] [-a aname] [-d delim] [-i text] [-n nchars] [-N nchars] [-p prompt] [-t time-
       out] [-u fd] [name ...]
              One line is read from the standard input, or from the file descriptor  fd  supplied
              as  an  argument  to  the -u option, split into words as described above under Word
              Splitting, and the first word is assigned to the first name, the second word to the
              second  name,  and  so on.  If there are more words than names, the remaining words
              and their intervening delimiters are assigned to the last name.  If there are fewer
              words read from the input stream than names, the remaining names are assigned empty
              values.  The characters in IFS are used to split the line into words using the same
              rules  the  shell  uses  for expansion (described above under Word Splitting).  The
              backslash character (\) may be used to remove any  special  meaning  for  the  next
              character read and for line continuation.  Options, if supplied, have the following
              meanings:
              -a aname
                     The words are assigned to sequential indices of the  array  variable  aname,
                     starting  at  0.   aname is unset before any new values are assigned.  Other
                     name arguments are ignored.
              -d delim
                     The first character of delim is used to terminate  the  input  line,  rather
                     than newline.  If delim is the empty string, read will terminate a line when
                     it reads a NUL character.
              -e     If the standard input is coming from  a  terminal,  readline  (see  READLINE
                     above)  is  used to obtain the line.  Readline uses the current (or default,
                     if line editing was not previously active) editing settings, but uses  Read-
                     line's default filename completion.
              -i text
                     If  readline is being used to read the line, text is placed into the editing
                     buffer before editing begins.
              -n nchars
                     read returns after reading nchars characters rather than waiting for a  com-
                     plete  line of input, but honors a delimiter if fewer than nchars characters
                     are read before the delimiter.
              -N nchars
                     read returns after reading exactly nchars characters rather than waiting for
                     a  complete line of input, unless EOF is encountered or read times out.  De-
                     limiter characters encountered in the input are not treated specially and do
                     not  cause  read  to return until nchars characters are read.  The result is
                     not split on the characters in IFS; the intent is that the variable  is  as-
                     signed exactly the characters read (with the exception of backslash; see the
                     -r option below).
              -p prompt
                     Display prompt on standard error, without a  trailing  newline,  before  at-
                     tempting to read any input.  The prompt is displayed only if input is coming
                     from a terminal.
              -r     Backslash does not act as an escape character.  The backslash is  considered
                     to  be  part  of  the line.  In particular, a backslash-newline pair may not
                     then be used as a line continuation.
              -s     Silent mode.  If input is coming from a terminal, characters are not echoed.
              -t timeout
                     Cause read to time out and return failure if a complete line of input (or  a
                     specified number of characters) is not read within timeout seconds.  timeout
                     may be a decimal number with a  fractional  portion  following  the  decimal
                     point.  This option is only effective if read is reading input from a termi-
                     nal, pipe, or other special file; it has no effect when reading from regular
                     files.  If read times out, read saves any partial input read into the speci-
                     fied variable name.  If timeout is 0, read returns immediately, without try-
                     ing  to  read  any  data.  The exit status is 0 if input is available on the
                     specified file descriptor, non-zero otherwise.  The exit status  is  greater
                     than 128 if the timeout is exceeded.
              -u fd  Read input from file descriptor fd.

              If  no  names  are  supplied, the line read is assigned to the variable REPLY.  The
              exit status is zero, unless end-of-file is encountered, read times  out  (in  which
              case  the status is greater than 128), a variable assignment error (such as assign-
              ing to a readonly variable) occurs, or an invalid file descriptor  is  supplied  as
              the argument to -u.
[...]

 

 

Súgó kimenet

read --help
read: read [-ers] [-a tömb] [-d elválasztó] [-i szöveg] [-n szám] [-N szám] [-p prompt] [-t időkeret] [-u fd] [név ...]
    Read a line from the standard input and split it into fields.
    
    Reads a single line from the standard input, or from file descriptor FD
    if the -u option is supplied.  The line is split into fields as with word
    splitting, and the first word is assigned to the first NAME, the second
    word to the second NAME, and so on, with any leftover words assigned to
    the last NAME.  Only the characters found in $IFS are recognized as word
    delimiters.
    
    If no NAMEs are supplied, the line read is stored in the REPLY variable.
    
    Options:
      -a array  assign the words read to sequential indices of the array
                variable ARRAY, starting at zero
      -d delim  continue until the first character of DELIM is read, rather
                than newline
      -e        use Readline to obtain the line
      -i text   use TEXT as the initial text for Readline
      -n nchars return after reading NCHARS characters rather than waiting
                for a newline, but honor a delimiter if fewer than
                NCHARS characters are read before the delimiter
      -N nchars return only after reading exactly NCHARS characters, unless
                EOF is encountered or read times out, ignoring any
                delimiter
      -p prompt output the string PROMPT without a trailing newline before
                attempting to read
      -r        do not allow backslashes to escape any characters
      -s        do not echo input coming from a terminal
      -t timeout        time out and return failure if a complete line of
                input is not read within TIMEOUT seconds.  The value of the
                TMOUT variable is the default timeout.  TIMEOUT may be a
                fractional number.  If TIMEOUT is 0, read returns
                immediately, without trying to read any data, returning
                success only if input is available on the specified
                file descriptor.  The exit status is greater than 128
                if the timeout is exceeded
      -u fd     read from file descriptor FD instead of the standard input
    
    Exit Status:
    The return code is zero, unless end-of-file is encountered, read times out
    (in which case it's greater than 128), a variable assignment error occurs,
    or an invalid file descriptor is supplied as the argument to -u.

 

Kapcsolódó tartalom

  •  

 

Címkék