Command Reference Guide

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STANDARD Printed by: Nora Chuang [nchuang] STANDARD
/build/1111/BRICK/man1/!!!intro.1
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c
col(1) col(1)
NAME
col - filter reverse line-feeds 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-line feeds (ESC-9 and
ESC-8). col is particularly useful for filtering multi-column 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-line feeds
(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 charactersSO (\016) and SI (\017) are assumed by col to start and end text in an alter-
nate 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, new-line, SI , SO , and
VT ,
(\013), and ESC followed by 7, 8,or9. The VT character is an alternate form of full reverse line-feed,
included for compatibility with some earlier programs of this type. All other non-printing 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.
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 non-empty string value, overrides the values of all the other internationalization vari-
ables.
LC_CTYPE determines the interpretation of text as single and/or multi-byte characters, the classification
of characters as printable, and the characters matched by character class expressions in regular expres-
sions.
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.
International Code Set Support
Single- and multi-byte character code sets are supported.
EXAMPLES
col is used most often with nroff and tbl. A common usage is:
HP-UX Release 11i: December 2000 − 1 − Section 1−−101
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