HP-UX Reference (11i v2 04/09) - 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 char-
acters 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
contains 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 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.
Section 1−−120 Hewlett-Packard Company − 1 − HP-UX 11i Version 2: September 2004