NAME¶
colcrt —
filter nroff output for CRT
previewing
SYNOPSIS¶
colcrt |
[-]
[-2]
[file ...] |
DESCRIPTION¶
The
colcrt utility 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 following options are available:
- -
- Suppress all underlining. This option is especially useful
for previewing allboxed tables from
tbl(1).
- -2
- Cause 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.
ENVIRONMENT¶
The
LANG
,
LC_ALL
and
LC_CTYPE
environment variables affect the execution of
colcrt as described in
environ(7).
EXIT STATUS¶
The
colcrt utility exits 0 on success, and >0 if
an error occurs.
EXAMPLES¶
A typical use of
colcrt would be
tbl exum2.n | nroff -ms | colcrt - | more
SEE ALSO¶
col(1),
more(1),
nroff(1),
troff(1),
ul(1)
HISTORY¶
The
colcrt command appeared in
3.0BSD.
BUGS¶
Should fold underlines onto blanks even with the
‘
-’ option so that a true underline character
would show.
Cannot 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.
Characters that take up more than one column position may not be underlined
correctly.