COLCRT(1)						      General Commands Manual							 COLCRT(1)

NAME

       colcrt - filter nroff output for CRT previewing

SYNOPSIS

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

DESCRIPTION

       Colcrt  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 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, 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.

       A typical use of colcrt would be

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

SEE ALSO

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

BUGS

       Should fold underlines onto blanks even with the `-' option so that a true underline character would show; if we did this, however,  colcrt
       wouldn't get rid of cu'd underlining completely.

       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.

3rd Berkeley Distribution					    May 7, 1986 							 COLCRT(1)