1.\" Copyright (c) 1980, 1990, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)colcrt.1 8.1 (Berkeley) 6/30/93 33.\" $FreeBSD: src/usr.bin/colcrt/colcrt.1,v 1.4.2.6 2003/02/24 23:04:38 trhodes Exp $ 34.\" $DragonFly: src/usr.bin/colcrt/colcrt.1,v 1.3 2006/02/17 19:38:58 swildner Exp $ 35.\" 36.Dd June 30, 1993 37.Dt COLCRT 1 38.Os 39.Sh NAME 40.Nm colcrt 41.Nd filter nroff output for CRT previewing 42.Sh SYNOPSIS 43.Nm 44.Op Fl 45.Op Fl \&2 46.Op Ar 47.Sh DESCRIPTION 48The 49.Nm 50utility provides virtual half-line and reverse line feed sequences 51for terminals without such capability, and on which overstriking 52is destructive. 53Half-line characters and underlining (changed to dashing `\-') 54are placed on new lines in between the normal output lines. 55.Pp 56The following options are available: 57.Bl -tag -width indent 58.It Fl 59Suppress all underlining. 60This option is especially useful for previewing 61.Em allboxed 62tables from 63.Xr tbl 1 . 64.It Fl 2 65Cause all half-lines to be printed, effectively double spacing the output. 66Normally, a minimal space output format is used which will suppress empty 67lines. 68The program never suppresses two consecutive empty lines, however. 69The 70.Fl 2 71option is useful for sending output to the line printer when the output 72contains superscripts and subscripts which would otherwise be invisible. 73.El 74.Sh EXAMPLES 75A typical use of 76.Nm 77would be 78.Bd -literal 79tbl exum2.n \&| nroff \-ms \&| colcrt \- \&| more 80.Ed 81.Sh SEE ALSO 82.Xr col 1 , 83.Xr more 1 , 84.Xr nroff 1 , 85.Xr troff 1 , 86.Xr ul 1 87.Sh HISTORY 88The 89.Nm 90command appeared in 91.Bx 3.0 . 92.Sh BUGS 93Should fold underlines onto blanks even with the 94.Sq Fl 95option so that 96a true underline character would show. 97.Pp 98Can't back up more than 102 lines. 99.Pp 100General overstriking is lost; 101as a special case 102.Ql \&| 103overstruck with 104.Ql \- 105or underline becomes 106.Ql \&+ . 107.Pp 108Lines are trimmed to 132 characters. 109.Pp 110Some provision should be made for processing superscripts and subscripts 111in documents which are already double-spaced. 112