filter reverse linefeeds
col [ -bfpx ]
col prepares output from processes, such as the
nroff text formatter for output on devices that limit or
do not allow reverse or half-line motions. col is
typically used to process nroff output text that contains
tables generated by the tbl program. A typical command
line might be:
tbl file | nroff | col | lpr
col takes the following options:
col assumes that the ASCII control characters
SO (octal 016) and SI (octal 017) start and end
text in an alternate character set. If you have a reverse linefeed
(ESC 7), reverse half linefeed (ESC 8), or
forward half linefeed (ESC 9), within an
SI-SO sequence, the ESC 7, 8 and 9 are
still recognized as line motions.
Assumes the output device in use is not capable of backspacing. If
two or more characters appear in the same place, col
outputs the last character read.
Allows forward half linefeeds. If not given, col accepts
half line motions in its input, but text that would appear between
lines is moved down to the next full line. Reverse full and half
linefeeds are never allowed with this option.
Prevents conversion of whitespace to tabs on output. col
normally converts whitespace to tabs wherever possible to shorten
Causes col to ignore unknown escape sequences found in its
input and pass them to the output as regular characters. Because
these characters are subject to overprinting from reverse line
motions, the use of this option is discouraged unless the user is
fully aware of the position of the escape sequences.
On input, the only control characters col accepts are
Space, Backspace, Tab, Return, Newline, reverse linefeed
(ESC 7), reverse half linefeed (ESC 8), forward
half linefeed (ESC 9), alternate character
start(SI), alternate character end (SO), and
vertical tag (VT). (The VT character is an
alternate form of full reverse linefeed, included for compatibility
with some earlier programs of this type.) All other non-printing
characters are ignored.
col returns the following values:
an error occurred
col cannot back up more than 128 lines.
col allows at most 800 characters, including backspaces,
on a line.
Vertical motions that would back up over the first line of the
document are ignored. Therefore, the first line must not contain
col is conformant with:
AT&T SVID Issue 2;
X/Open CAE Specification, Commands and Utilities, Issue 4, 1992: note that this command is marked as to be
© 2005 The SCO Group, Inc. All rights reserved.
SCO OpenServer Release 6.0.0 -- 03 June 2005