col(1)                   USER COMMANDS                     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  dev-
     ice  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.



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col(1)                   USER COMMANDS                     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.





































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