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.\"     @(#)colcrt.1	8.1 (Berkeley) 6/30/93
.\"
.TH COLCRT "1" "September 2011" "util-linux" "User Commands"
.SH NAME
colcrt \- filter nroff output for CRT previewing
.SH SYNOPSIS
.B colcrt
[options]
.RI [ file ...]
.SH DESCRIPTION
.B colcrt
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.
.SH OPTIONS
.TP
\fB\-\fR, \fB\-\-no\-underlining\fR
Suppress all underlining.  This option is especially useful for previewing
.I allboxed
tables from
.BR tbl (1).
.TP
\fB\-2\fR, \fB\-\-half\-lines\fR
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
.B \-2
option is useful for sending output to the line printer when the output
contains superscripts and subscripts which would otherwise be invisible.
.TP
\fB\-V\fR, \fB\-\-version\fR
Display version information and exit.
.TP
\fB\-h\fR, \fB\-\-help\fR
Display help text and exit.
.SH EXAMPLES
A typical use of
.B colcrt
would be:
.PP
.RS
.B tbl exum2.n \&| nroff \-ms \&| colcrt \- \&| more
.RE
.SH SEE ALSO
.BR col (1),
.BR more (1),
.BR nroff (1),
.BR troff (1),
.BR ul (1)
.SH BUGS
Should fold underlines onto blanks even with the
.B '\-'
option so that a true underline character would show.
.PP
Can't back up more than 102 lines.
.PP
General overstriking is lost; as a special case '|' overstruck with '\-' or
underline becomes '+'.
.PP
Lines are trimmed to 132 characters.
.PP
Some provision should be made for processing superscripts and subscripts in
documents which are already double-spaced.
.SH HISTORY
The
.B colcrt
command appeared in 3.0BSD.
.SH AVAILABILITY
The colcrt command is part of the util-linux package and is available from
.UR https://\:www.kernel.org\:/pub\:/linux\:/utils\:/util-linux/
Linux Kernel Archive
.UE .