HP-UX Reference (11i v2 07/12) - 1 User Commands A-M (vol 1)

c
col(1) col(1)
NAME
col - filter reverse linefeeds and backspaces
SYNOPSIS
col [-blfxp]
DESCRIPTION
col reads from the standard input and writes onto the standard output. It performs the line overlays
implied by reverse line feeds (ASCII code ESC-7
), and by forward and reverse half-linefeeds (
ESC-9 and
ESC-8). col is particularly useful for filtering multicolumn output made with the
nroff .rt com-
mand, and output resulting from use of the
tbl preprocessor (see nroff(1) and tbl(1)).
If the
-b option is given, col
assumes that the output device in use is not capable of backspacing. In this
case, if two or more characters are to appear in the same place, only the last one read is output.
If the
-l option is given,
col assumes the output device is a line printer (rather than a character printer)
and removes backspaces in favor of multiply overstruck full lines. It generates the minimum number of
print operations necessary to generate the required number of overstrikes. (All but the last print operation
on a line are separated by carriage returns (\r); the last print operation is terminated by a newline (\n).)
Although
col accepts half-line motions in its input, it normally does not emit them on output. Instead,
text that would appear between lines is moved to the next lower full-line boundary. This treatment can be
suppressed by the -f (fine) option; in this case, the output from col may contain forward half-linefeeds
(ESC-9), but will still never contain either kind of reverse line motion.
Unless the
-x option is given, col converts white space to tabs on output wherever possible to shorten
printing time.
The ASCII control characters SO (\016) and SI (\017) are assumed by col to start and end text in an
alternate character set. The character set to which each input character belongs is remembered, and, on
output, SI and SO characters are generated as appropriate to ensure that each character is printed in the
correct character set.
On input, the only control characters accepted are space, backspace, tab, return, newline, SI , SO , and VT ,
(\013), and ESC followed by 7, 8,or9. The VT character is an alternate form of full reverse linefeed,
included for compatibility with some earlier programs of this type. All other nonprinting characters are
ignored.
Normally,
col ignores any unrecognized escape sequences found in its input; the -p option can be used
to cause
col to output these sequences as regular characters, subject to overprinting from reverse line
motions. The use of this option is highly discouraged unless the user is fully aware of the textual position of
the escape sequences.
Notes
The input format accepted by col matches the output produced by nroff with either the -T37
or
-Tlp options. Use -T37 (and the -f option of col) if the ultimate disposition of the output of
col is a
device that can interpret half-line motions, and
-Tlp otherwise.
EXTERNAL INFLUENCES
Environment Variables
LANG provides a default value for the internationalization variables that are unset or null. If
LANG is
unset or null, the default value of "C" (see lang(5)) is used. If any of the internationalization variables con-
tains an invalid setting,
col will behave as if all internationalization variables are set to "C". See
environ(5).
LC_ALL If set to a nonempty string value, overrides the values of all the other internationalization vari-
ables.
LC_CTYPE determines the interpretation of text as single and/or multibyte characters, the classification of
characters as printable, and the characters matched by character class expressions in regular expressions.
LC_MESSAGES determines the locale that should be used to affect the format and contents of diagnostic
messages written to standard error and informative messages written to standard output.
NLSPATH determines the location of message catalogues for the processing of LC_MESSAGES .
HP-UX 11i Version 2: December 2007 Update − 1 − Hewlett-Packard Company 165