col(1) User Commands col(1)
col - reverse line-feeds filter
The col utility reads from the standard input and writes to the stan-
dard output. It performs the line overlays implied by reverse line-
feeds, and by forward and reverse half-line-feeds. Unless -x is used,
all blank characters in the input will be converted to tab characters
wherever possible. col is particularly useful for filtering multi-col-
umn output made with the .rt command of nroff(1) and output resulting
from use of the tbl(1) preprocessor.
The ASCII control characters SO and SI are assumed by col to start and
end text in an alternative 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 written in the correct character set.
On input, the only control characters accepted are space, backspace,
tab, carriage-return and newline characters, SI, SO, VT, reverse line-
feed, forward half-line-feed and reverse half-line-feed. The VT charac-
ter is an alternative form of full reverse line-feed, included for com-
patibility with some earlier programs of this type. The only other
characters to be copied to the output are those that are printable.
The ASCII codes for the control functions and line-motion sequences
mentioned above are as given in the table below. ESC stands for the
ASCII escape character, with the octal code 033; ESC- means a sequence
of two characters, ESC followed by the character x.
tab(); lw(2.750000i) lw(2.750000i). reverse line-feedESC-7 reverse
half-line-feedESC-8 forward half-line-feedESC-9 vertical-tab (VT)013
start-of-text (SO)016 end-of-text (SI)017
-b Assume 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 will be out-
-f Although col accepts half-line motions in its input, it nor-
mally 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.
-p Normally, col will ignore any escape sequences unknown to it
that are found in its input; the -p option may 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.
-x Prevent col from converting blank characters to tab characters
on output wherever possible. Tab stops are considered to be at
each column position n such that n modulo 8 equals 1.
See environ(5) for descriptions of the following environment variables
that affect the execution of col: LC_CTYPE, LC_MESSAGES, and NLSPATH.
The following error values are returned:
0 Successful completion.
>>0 An error occurred.
See attributes(5) for descriptions of the following attributes:
tab() allbox; cw(2.750000i)| cw(2.750000i) lw(2.750000i)|
lw(2.750000i). ATTRIBUTE TYPEATTRIBUTE VALUE AvailabilitySUNWesu
nroff(1), tbl(1), ascii(5), attributes(5), environ(5)
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 will be a device
that can interpret half-line motions, and -Tlp otherwise.
col cannot back up more than 128 lines or handle more than 800 charac-
ters per line.
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.
SunOS 5.10 1 Feb 1995 col(1)