COLCRT(1) MachTen Reference 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 destruc-
tive. Half-line characters and underlining (changed to dashing ‘-’) are
placed on new lines in between the normal output lines.

Available options:

- 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 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.

EXAMPLES
A typical use of colcrt would be

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

SEE ALSO
nroff(1), 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.

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.

HISTORY
The colcrt command appeared in 3.0BSD.

3rd Berkeley Distribution June 30, 1993 1