col Man page

COL(1) BSD General Commands Manual COL(1)


col — filter reverse line feeds from input


col [-bfhpx] [-l num]


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 and tbl.

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

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

-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.

The control sequences for carriage motion that col understands and their
decimal values are listed in the following table:

ESC-7 reverse line feed (escape then 7)
ESC-8 half reverse line feed (escape then 8)
ESC-9 half forward line feed (escape then 9)
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 dis‐
play a warning message.

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

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


colcrt, expand, nroff, tbl

The col utility conforms to Version 2 of the Single UNIX Specification

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

BSD August 4, 2004 BSD