COLCRT(1) BSD Reference Manual COLCRT(1)
colcrt - filter nroff output for CRT previewing
colcrt [-] [-2] [file ...]
colcrt provides virtual half-line and reverse line feed sequences for terminals without such capability, and on which overstriking is destruc- tive. Half-line characters and underlining (changed to dashing '-') are placed on new lines in between the normal output lines. The options are as follows: - Suppress all underlining. This option is especially useful for previewing allboxed tables from tbl(1). -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 con- secutive empty lines, however. The -2 option is useful for send- ing output to the line printer when the output contains super- scripts and subscripts which would otherwise be invisible.
A typical use of colcrt would be $ tbl exum2.n | nroff -ms | colcrt - | more
col(1), more(1), nroff(1), troff(1), ul(1)
The colcrt command appeared in 3.0BSD.
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. MirBSD #10-current June 30, 1993 1