NAME

     col — filter reverse line feeds from input

SYNOPSIS

     col [-bfhpx] [-l num]

DESCRIPTION

     The col utility filters out reverse (and half reverse) line feeds so that the output is in
     the correct order with only forward and half forward line feeds, and replaces white-space
     characters with tabs where possible.  This can be useful in processing the output of
     nroff(1) and tbl(1).

     The col utility reads from the standard input and writes to the standard output.

     The options are as follows:

     -b      Do not output any backspaces, printing only the last character written to each
             column position.

     -f      Forward half line feeds are permitted (``fine'' mode).  Normally characters printed
             on a half line boundary are printed on the following line.

     -h      Do not output multiple spaces instead of tabs (default).

     -l num  Buffer at least num lines in memory.  By default, 128 lines are buffered.

     -p      Force unknown control sequences to be passed through unchanged.  Normally, col will
             filter out any control sequences from the input other than those recognized and
             interpreted by itself, which are listed below.

     -x      Output multiple spaces instead of tabs.

     In the input stream, col understands both the escape sequences of the form escape-digit
     mandated by Version 2 of the Single UNIX Specification (“SUSv2”) and the traditional BSD
     format escape-control-character.  The control sequences for carriage motion and their ASCII
     values are as follows:

     ESC-BELL         reverse line feed (escape then bell).
     ESC-7            reverse line feed (escape then 7).
     ESC-BACKSPACE    half reverse line feed (escape then backspace).
     ESC-8            half reverse line feed (escape then 8).
     ESC-TAB          half forward line feed (escape than tab).
     ESC-9            half forward line feed (escape then 9).  In -f mode, this sequence may also
                      occur in the output stream.
     backspace        moves back one column (8); ignored in the first column
     carriage return  (13)
     newline          forward line feed (10); also does carriage return
     shift in         shift to normal character set (15)
     shift out        shift to alternate character set (14)
     space            moves forward one column (32)
     tab              moves forward to next tab stop (9)
     vertical tab     reverse line feed (11)

     All unrecognized control characters and escape sequences are discarded.

     The col utility keeps track of the character set as characters are read and makes sure the
     character set is correct when they are output.

     If the input attempts to back up to the last flushed line, col will display a warning
     message.

ENVIRONMENT

     The LANG, LC_ALL and LC_CTYPE environment variables affect the execution of col as described
     in environ(7).

EXIT STATUS

     The col utility exits 0 on success, and >0 if an error occurs.

SEE ALSO

     colcrt(1), expand(1), nroff(1), tbl(1)

STANDARDS

     The col utility conforms to Version 2 of the Single UNIX Specification (“SUSv2”).

HISTORY

     A col command appeared in Version 6 AT&T UNIX.