COL(1)

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 (e.g., ASCII code ESC-7), and by forward and reverse half-line feeds (i.e., ESC-9 and ESC-8). col is particularly useful for filtering multiple-column output made with the command of nroff and output resulting from use of the tbl preprocessor.

[-b]
col assumes that the output device in use is not capable of backspacing. If two or more characters are to appear in the same place, only the last one read will be output.

    [-f]
suppresses partial line motions.
    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 is suppressed by the [-f] (fine) option. The output from col may contain forward half-line feeds (i.e., ESC-9), but will still never contain either kind of reverse line motion.

    [-x]
suppresses conversion of white space to tabs to shorten printing time.

    [-p]
output unknown escape sequences as regular characters, subject
    to overprinting from reverse line motions; normally, col ignores unknown escape sequences. The use of this option is highly discouraged unless the user is fully aware of the textual position of the escape sequences.

col assumes the ASCII control characters SO and SI 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, col accepts only the control characters space, backspace, tab, return, newline, SI, SO, VT and ESC-7, ESC-8, or ESC-9. The VT character is an alternate form of full reverse line-feed, included for compatibility with earlier similar programs. All other non-printing characters are ignored.

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 will be a device that can interpret half-line motions; use [-Tlp] otherwise.

BUGS
Cannot back up more than 128 lines.

Allows at most 800 characters, including backspaces, on a 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.

SEE ALSO
nroff(1), tbl(1)