COL(1)                                                     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
          standard 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
          particularly 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
          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.

          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
          character 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)                                                     COL(1)



     SEE ALSO
          nroff(1), tbl(1) in the DOCUMENTER's WORKBENCH Software
          Release 2.0 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.

     BUGS
          Cannot back up more than 128 lines.
          Allows at most 800 characters, including backspaces, on a
          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.

     ORIGIN
          AT&T V.3


































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