COL(1) General Commands Manual COL(1)
col - filter reverse line feeds
col [ -bfh ]
Col reads the standard input and writes the standard output. It per‐
forms 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) pre‐
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 con‐
tain 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 neces‐
sary to maintain the correct treatment of each character.
If the -h option is given, col converts white space to tabs to shorten
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 conven‐
tions. All other non-printing characters are ignored.
Can't back up more than 128 lines.
No more than 800 characters, including backspaces, on a line.
7th Edition May 16, 1986 COL(1)