col - filter reverse paper motions from nroff output for display on a
col [ -bfhp ]
SYSTEM V SYNOPSIS
/usr/5bin/col [ -bfpx ]
The System V version of this command is available with the System V
software installation option. Refer to for information on how to
install optional software.
col copies the standard input to the standard output and performs line
overlays implied by reverse LINEFEED characters (ESC-7 in ASCII) and by
forward and reverse half LINEFEED characters (ESC-9 and ESC-8). col is
particularly useful for filtering multicolumn output made with the .rt
command of nroff(1), and output resulting from use of the tbl(1) pre-
The control characters SO (ASCII code 017), and SI (016) are assumed to
start and end text in an alternate character set. The character set
(primary or alternate) associated with each printing character read is
remembered; on output, SO and SI characters are generated where neces-
sary to maintain the correct treatment of each character.
All control characters are removed from the input except SPACE,
BACKSPACE, TAB, RETURN, NEWLINE, ESC (033) followed by one of 7, 8, 9,
SI , SO , and VT (013). This last character is an alternate form of
full reverse LINEFEED, for compatibility with some other hardware con-
ventions. All other non-printing characters are ignored.
SYSTEM V DESCRIPTION
The System V version of col converts SPACE to TAB characters by
-b The output device in use is not capable of backspacing. In this
case, if several characters are to appear in the same place,
only the last one read will be taken.
-f Fine. Although col accepts half line motions in its input, it
normally does not produce them on output. Instead, text that
would appear between lines is moved to the next lower full-line
boundary. The -f option suppresses this treatment. In this case
the output from col may contain forward half LINEFEED characters
(ESC-9), but will still never contain either kind of reverse
-h Convert strings of blanks to TAB characters to decrease the
-p Pass escape-sequences that col does not know about to the out-
put, rather than stripping them out. This option is highly dis-
couraged unless you are fully aware of the position of the
escape sequences within the text.
SYSTEM V OPTIONS
-x Suppress converting SPACE characters to TAB characters.
The environment variables LC_CTYPE, LANG, and LC_default control the
character classification throughout col. On entry to col, these envi-
ronment variables are checked in the following order: LC_CTYPE, LANG,
and LC_default. When a valid value is found, remaining environment
variables for character classification are ignored. For example, a new
setting for LANG does not override the current valid character classi-
fication rules of LC_CTYPE. When none of the values is valid, the
shell character classification defaults to the POSIX.1 "C" locale.
nroff(1), tbl(1), troff(1), locale(5), iso_8859_1(7)
col cannot back up more than 128 lines.
At most 1600 characters, including BACKSPACE characters, are allowed on
Local vertical motions that would result in backing up over the first
line of the document are ignored. As a result, the first line must not
have any superscripts.
2 October 1989 COL(1V)