colcrt(1)
NAME
colcrt − filter nroff output for CRT previewing
SYNTAX
colcrt [ − ] [ −2 ] [ file ... ]
DESCRIPTION
The colcrt command 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
RESTRICTIONS
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.