COL(1) — Silicon Graphics
NAME
col − filter reverse line-feeds
SYNOPSIS
col [ −bfpx ] [ −
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 made with the .rt command of nroff and output resulting from use of the tbl(1) preprocessor.
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 will be output.
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 will convert white space to tabs wherever possible to shorten printing time.
The ASCII control chracters SO (\017) and SI (\016)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 SO and SI 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, SO, SI, VT( 13), and ESC followed by 7,8, or 9 . 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 will ignore any escape sequences unknown to it that are found in its input; the 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 options is highly discourage unless the user if fully aware of the textual position of the escape sequences.
SEE ALSO
Version 2.5 — April 22, 1987