COLCRT(1)
NAME
colcrt − filter nroff output for CRT previewing
USAGE
colcrt [ − ] [ −2 ] [ file ... ]
DESCRIPTION
Colcrt provides virtual half-line and reverse line feed sequences for terminals without such capability, and for which overstriking is destructive. Half-line characters and underscores (changed to dashes) are placed on newlines between the normal output lines.
OPTIONS
− Suppress all underscoring. This option is especially useful when you want to preview tables that use the allbox formatting option of tbl (1).
−2 Print all half-lines, effectively double-spacing the output. A minimal space output format that suppresses empty lines is normally used. The program never suppresses two consecutive empty lines, however. This option is useful when you want to send output containing superscripts and subscripts to the line printer (these characters would otherwise be invisible).
EXAMPLE
A typical use of colcrt is shown here:
tbl exum2.n | nroff −ms | colcrt − | more
CAUTIONS
Colcrt does not fold underscores onto blanks even with the dash (−) option so that a true underscore character shows.
Colcrt cannot back up more than 102 lines.
General overstriking is lost. As a special case, a pipe character (|) overstruck with a dash (−) or underscore becomes a plus sign (+).
Lines are trimmed to 132 characters.
No provision is made for processing superscripts and subscripts in documents that are already double-spaced.