COL(1)              RISC/os Reference Manual               COL(1)



NAME
     col - filter reverse line-feeds

SYNOPSIS
     col [-b] [-f] [-x] [-p]

DESCRIPTION
     col reads from the standard input and writes onto the stan-
     dard 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 particu-
     larly useful for filtering multicolumn output 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 nor-
     mally 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.

     Unless the x option is given, col will convert white space
     to tabs on output wherever possible to shorten printing
     time.

     The ASCII control characters SO (\017) and SI (\016) are
     assumed by col to start and end text in an alternate charac-
     ter 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, the only control characters accepted are space,
     backspace, tab, return, new-line, SI, SO, VT (\013), 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 p 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 option is highly discouraged unless the user is
     fully aware of the textual position of the escape sequences.



                        Printed 11/19/92                   Page 1

COL(1)              RISC/os Reference Manual               COL(1)



SEE ALSO
     ascii(5)
     nroff(1), tbl(1) in the DOCUMENTER'S WORKBENCH Software
     Technical Discussion and Reference Manual .

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, and -Tlp otherwise.

     col cannot back up more than 128 lines or handle more than
     800 characters per 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.





































 Page 2                 Printed 11/19/92