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 overstriking 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, LC_ALL and LC_CTYPE environment variables affect  the  execution  of  colcrt  as  described  in
       environ(7).

EXIT STATUS

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

EXAMPLES

       A typical use of colcrt would be

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

SEE ALSO

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

HISTORY

       The colcrt command appeared in 3.0BSD.

BUGS

       Should  fold  underlines  onto  blanks  even with the ‘-’ option so that a true underline character would
       show.

       Cannot 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 underlined correctly.

Debian                                            July 31, 2004                                        COLCRT(1)