1.\" $NetBSD: col.1,v 1.10 2012/03/22 07:58:18 wiz Exp $ 2.\" 3.\" Copyright (c) 1990, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" This code is derived from software contributed to Berkeley by 7.\" Michael Rendell. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 3. Neither the name of the University nor the names of its contributors 18.\" may be used to endorse or promote products derived from this software 19.\" without specific prior written permission. 20.\" 21.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31.\" SUCH DAMAGE. 32.\" 33.\" @(#)col.1 8.1 (Berkeley) 6/29/93 34.\" 35.Dd February 22, 1999 36.Dt COL 1 37.Os 38.Sh NAME 39.Nm col 40.Nd filter reverse line feeds from input 41.Sh SYNOPSIS 42.Nm 43.Op Fl bfpx 44.Op Fl l Ar num 45.Sh DESCRIPTION 46.Nm 47filters out reverse (and half reverse) line feeds so that the output is 48in the correct order with only forward and half forward line 49feeds, and replaces white-space characters with tabs where possible. 50This can be useful in processing the output of 51.Xr nroff 1 52and 53.Xr tbl 1 . 54.Pp 55.Nm 56reads from the standard input and writes to the standard output. 57.Pp 58The options are as follows: 59.Bl -tag -width "-l num " 60.It Fl b 61Do not output any backspaces, printing only the last character 62written to each column position. 63.It Fl f 64Forward half line feeds are permitted (``fine'' mode). 65Normally characters printed on a half line boundary are printed 66on the following line. 67.It Fl p 68Force unknown control sequences to be passed through unchanged. 69Normally, 70.Nm 71will filter out any control sequences from the input other than those 72recognized and interpreted by itself, which are listed below. 73.It Fl x 74Output multiple spaces instead of tabs. 75.It Fl l Ar num 76Buffer at least 77.Ar num 78lines in memory. 79By default, 128 lines are buffered. 80.El 81.Pp 82The control sequences for carriage motion that 83.Nm 84understands and their decimal values are listed in the following 85table: 86.Pp 87.Bl -tag -width "carriage return" -compact 88.It ESC\-7 89reverse line feed (escape then 7) 90.It ESC\-8 91half reverse line feed (escape then 8) 92.It ESC\-9 93half forward line feed (escape then 9) 94.It backspace 95moves back one column (8); ignored in the first column 96.It carriage return 97(13) 98.It newline 99forward line feed (10); also does carriage return 100.It shift in 101shift to normal character set (15) 102.It shift out 103shift to alternative character set (14) 104.It space 105moves forward one column (32) 106.It tab 107moves forward to next tab stop (9) 108.It vertical tab 109reverse line feed (11) 110.El 111.Pp 112All unrecognized control characters and escape sequences are 113discarded. 114.Pp 115.Nm 116keeps track of the character set as characters are read and makes 117sure the character set is correct when they are output. 118.Pp 119If the input attempts to back up to the last flushed line, 120.Nm 121will display a warning message. 122.Sh SEE ALSO 123.Xr expand 1 , 124.Xr nroff 1 , 125.Xr tbl 1 126.Sh STANDARDS 127The 128.Nm 129utility conforms to 130.St -xpg4.2 . 131The 132.Fl l 133option is an extension to the standard. 134.Sh HISTORY 135A 136.Nm 137command appeared in 138.At v6 . 139