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.