1.\" Copyright (c) 1990, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" Michael Rendell. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. All advertising materials mentioning features or use of this software 16.\" must display the following acknowledgement: 17.\" This product includes software developed by the University of 18.\" California, Berkeley and its contributors. 19.\" 4. Neither the name of the University nor the names of its contributors 20.\" may be used to endorse or promote products derived from this software 21.\" without specific prior written permission. 22.\" 23.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33.\" SUCH DAMAGE. 34.\" 35.\" @(#)col.1 8.1 (Berkeley) 6/29/93 36.\" $FreeBSD$ 37.\" 38.Dd August 4, 2004 39.Dt COL 1 40.Os 41.Sh NAME 42.Nm col 43.Nd filter reverse line feeds from input 44.Sh SYNOPSIS 45.Nm 46.Op Fl bfhpx 47.Op Fl l Ar num 48.Sh DESCRIPTION 49The 50.Nm 51utility filters out reverse (and half reverse) line feeds so that the output is 52in the correct order with only forward and half forward line 53feeds, and replaces white-space characters with tabs where possible. 54This can be useful in processing the output of 55.Xr nroff 1 56and 57.Xr tbl 1 . 58.Pp 59The 60.Nm 61utility reads from the standard input and writes to the standard output. 62.Pp 63The options are as follows: 64.Bl -tag -width indent 65.It Fl b 66Do not output any backspaces, printing only the last character 67written to each column position. 68.It Fl f 69Forward half line feeds are permitted (``fine'' mode). 70Normally characters printed on a half line boundary are printed 71on the following line. 72.It Fl h 73Do not output multiple spaces instead of tabs (default). 74.It Fl l Ar num 75Buffer at least 76.Ar num 77lines in memory. 78By default, 128 lines are buffered. 79.It Fl p 80Force unknown control sequences to be passed through unchanged. 81Normally, 82.Nm 83will filter out any control sequences from the input other than those 84recognized and interpreted by itself, which are listed below. 85.It Fl x 86Output multiple spaces instead of tabs. 87.El 88.Pp 89The control sequences for carriage motion that 90.Nm 91understands and their decimal values are listed in the following 92table: 93.Pp 94.Bl -tag -width "carriage return" -compact 95.It ESC\-7 96reverse line feed (escape then 7) 97.It ESC\-8 98half reverse line feed (escape then 8) 99.It ESC\-9 100half forward line feed (escape then 9) 101.It backspace 102moves back one column (8); ignored in the first column 103.It carriage return 104(13) 105.It newline 106forward line feed (10); also does carriage return 107.It shift in 108shift to normal character set (15) 109.It shift out 110shift to alternate character set (14) 111.It space 112moves forward one column (32) 113.It tab 114moves forward to next tab stop (9) 115.It vertical tab 116reverse line feed (11) 117.El 118.Pp 119All unrecognized control characters and escape sequences are 120discarded. 121.Pp 122The 123.Nm 124utility keeps track of the character set as characters are read and makes 125sure the character set is correct when they are output. 126.Pp 127If the input attempts to back up to the last flushed line, 128.Nm 129will display a warning message. 130.Sh ENVIRONMENT 131The 132.Ev LANG , LC_ALL 133and 134.Ev LC_CTYPE 135environment variables affect the execution of 136.Nm 137as described in 138.Xr environ 7 . 139.Sh EXIT STATUS 140.Ex -std 141.Sh SEE ALSO 142.Xr colcrt 1 , 143.Xr expand 1 , 144.Xr nroff 1 , 145.Xr tbl 1 146.Sh STANDARDS 147The 148.Nm 149utility conforms to 150.St -susv2 . 151.Sh HISTORY 152A 153.Nm 154command 155appeared in 156.At v6 . 157