COL(1)

NAME
col - filter reverse line feeds

SYNOPSIS
col [-bfxp]

DESCRIPTION
Col reads the standard input and writes the standard output. It performs the line overlays implied by reverse line feeds (ESC-7 in ASCII) and by forward and reverse half line feeds (ESC-9 and ESC-8). Col is particularly useful for filtering multicolumn output made with the `.rt' command of nroff and output resulting from use of the tbl(1) preprocessor.

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.

If the -b option is given, col assumes that the output device in use is not capable of backspacing. In this case, if several characters are to appear in the same place, only the last one read will be taken.

The control characters SO (ASCII code 017), and SI (016) are assumed to start and end text in an alternate character set. The character set (primary or alternate) associated with each printing character read is remembered; on output, SO and SI characters are generated where necessary to maintain the correct treatment of each character.

Col normally converts white space to tabs to shorten printing time. If the -x option is given, this conversion is suppressed.

All control characters are removed from the input except space, backspace, tab, return, newline, ESC (033) followed by one of 7, 8, 9, SI, SO, and VT (013). This last character is an alternate form of full reverse line feed, for compatibility with some other hardware conventions. With the -p option, all escape sequences are passed through, but col does not perform any interpretation of sequences unknown to it so its output may not be appropriate with this option. All other non-printing characters are ignored.

ENVIRONMENT VARIABLES

LANG, LC_ALL
    See locale(7).

LC_CTYPE
    Determines the mapping of bytes to characters, the set of printable characters, and the width of characters.

SEE ALSO
troff(1), tbl(1)

NOTES
Can't back up more than 256 lines.