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