colcrt(1)                                               colcrt(1)



     NAME
          colcrt - filter nroff output for terminal previewing

     SYNOPSIS
          colcrt [-] [-2] [file]

     DESCRIPTION
          colcrt provides virtual half-line and reverse line feed se-
          quences for terminals without such capability, and on which
          overstriking is destructive.  Half-line characters and
          underlining (changed to dashing ``-'') are placed on new-
          lines in between the normal output lines.

          The optional - suppresses all underlining.  It is especially
          useful for previewing allboxed tables from tbl(1).

          The option -2 causes all half-lines to be printed, effec-
          tively double spacing the output.  Normally, a minimal space
          output format is used which will suppress empty lines.  The
          program never suppresses two consecutive empty lines, howev-
          er.  The -2 flag option is useful for sending output to the
          line printer when the output contains superscripts and sub-
          scripts which would otherwise be invisible.

          A typical use of colcrt would be

             tbl exum2.n | nroff -mm | colcrt | more


     FILES
          /usr/ucb/colcrt

     SEE ALSO
          col(1), more(1), nroff(1), troff(1), ul(1).

     BUGS
          Should fold underlines onto blanks even with the - flag op-
          tion so that a true underline character would show; if we
          did this, however, colcrt wouldn't get rid of cu'd underlin-
          ing completely.

          Can't back up more than 102 lines.

          General overstriking is lost; as a special case ``|'' over-
          struck with ``-'' or underline becomes ``+''.

          Lines are trimmed to 132 characters.

          Some provision should be made for processing superscripts
          and subscripts in documents which are already double-spaced.





     April, 1990                                                     1