'\" t
.\"     Title: colcrt
.\"    Author: [see the "AUTHOR(S)" section]
.\" Generator: Asciidoctor 2.0.20
.\"      Date: 2023-10-23
.\"    Manual: User Commands
.\"    Source: util-linux 2.39.3
.\"  Language: English
.\"
.TH "COLCRT" "1" "2023-10-23" "util\-linux 2.39.3" "User Commands"
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.SH "NAME"
colcrt \- filter nroff output for CRT previewing
.SH "SYNOPSIS"
.sp
\fBcolcrt\fP [options] [\fIfile\fP ...]
.SH "DESCRIPTION"
.sp
\fBcolcrt\fP 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 `\-\*(Aq) are placed on new lines in between the normal output lines.
.SH "OPTIONS"
.sp
\fB\-\fP, \fB\-\-no\-underlining\fP
.RS 4
Suppress all underlining. This option is especially useful for previewing \fIallboxed\fP tables from \fBtbl\fP(1).
.RE
.sp
\fB\-2\fP, \fB\-\-half\-lines\fP
.RS 4
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 \fB\-2\fP option is useful for sending output to the line printer when the output contains superscripts and subscripts which would otherwise be partially invisible.
.RE
.sp
\fB\-h\fP, \fB\-\-help\fP
.RS 4
Display help text and exit.
.RE
.sp
\fB\-V\fP, \fB\-\-version\fP
.RS 4
Print version and exit.
.RE
.SH "HISTORY"
.sp
The \fBcolcrt\fP command appeared in 3.0BSD.
.SH "BUGS"
.sp
Should fold underlines onto blanks even with the \fB\-\fP option so that a true underline character would show.
.sp
Can\(cqt back up more than 102 lines.
.sp
General overstriking is lost; as a special case \*(Aq|\*(Aq overstruck with \*(Aq\-\*(Aq or underline becomes \*(Aq+\*(Aq.
.sp
Lines are trimmed to 132 characters.
.sp
Some provision should be made for processing superscripts and subscripts in documents which are already double\-spaced.
.SH "EXAMPLES"
.sp
A typical use of \fBcolcrt\fP would be:
.RS 3
.ll -.6i
.sp
\fBtbl exum2.n | nroff \-ms | colcrt \- | more\fP
.br
.RE
.ll
.SH "SEE ALSO"
.sp
\fBcol\fP(1),
\fBmore\fP(1),
\fBnroff\fP(1),
\fBtroff\fP(1),
\fBul\fP(1)
.SH "REPORTING BUGS"
.sp
For bug reports, use the issue tracker at \c
.URL "https://github.com/util\-linux/util\-linux/issues" "" "."
.SH "AVAILABILITY"
.sp
The \fBcolcrt\fP command is part of the util\-linux package which can be downloaded from \c
.URL "https://www.kernel.org/pub/linux/utils/util\-linux/" "Linux Kernel Archive" "."