COLCRT(1)                 BSD General Commands Manual                COLCRT(1)

NAME
     colcrt -- filter nroff output for CRT previewing

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

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

     The following options are available:

     -       Suppress all underlining.  This option is especially useful for
             previewing allboxed tables from tbl(1).

     -2      Cause all half-lines to be printed, effectively 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, however.  The -2 option is useful
             for sending output to the line printer when the output contains
             superscripts and subscripts which would otherwise be invisible.

ENVIRONMENT
     The LANG, LCAL and LCTYPE environment variables affect the execution
     of colcrt as described in environ(7).

EXAMPLES
     A typical use of colcrt would be

     tbl exum2.n  nroff -ms  colcrt -  more

DIAGNOSTICS
     The colcrt utility exits 0 on success, and >0 if an error occurs.

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

BUGS
     Should fold underlines onto blanks even with the `-' option so that a
     true underline character would show.

     Can't back up more than 102 lines.

     General overstriking is lost; as a special case `' overstruck 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.

     Characters that take up more than one column position may not be under-
     lined correctly.

HISTORY
     The colcrt command appeared in 3.0BSD.

BSD                              July 31, 2004                             BSD