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: src/usr.bin/col/col.1,v 1.4.2.7 2002/07/15 04:32:27 keramida Exp $ 37.\" $DragonFly: src/usr.bin/col/col.1,v 1.2 2003/06/17 04:29:25 dillon Exp $ 38.\" 39.Dd June 29, 1993 40.Dt COL 1 41.Os 42.Sh NAME 43.Nm col 44.Nd filter reverse line feeds from input 45.Sh SYNOPSIS 46.Nm 47.Op Fl bfhpx 48.Op Fl l Ar num 49.Sh DESCRIPTION 50The 51.Nm 52utility filters out reverse (and half reverse) line feeds so that the output is 53in the correct order with only forward and half forward line 54feeds, and replaces white-space characters with tabs where possible. 55This can be useful in processing the output of 56.Xr nroff 1 57and 58.Xr tbl 1 . 59.Pp 60The 61.Nm 62utility reads from the standard input and writes to the standard output. 63.Pp 64The options are as follows: 65.Bl -tag -width indent 66.It Fl b 67Do not output any backspaces, printing only the last character 68written to each column position. 69.It Fl f 70Forward half line feeds are permitted (``fine'' mode). 71Normally characters printed on a half line boundary are printed 72on the following line. 73.It Fl h 74Don't output multiple spaces instead of tabs (default). 75.It Fl l Ar num 76Buffer at least 77.Ar num 78lines in memory. 79By default, 128 lines are buffered. 80.It Fl p 81Force unknown control sequences to be passed through unchanged. 82Normally, 83.Nm 84will filter out any control sequences from the input other than those 85recognized and interpreted by itself, which are listed below. 86.It Fl x 87Output multiple spaces instead of tabs. 88.El 89.Pp 90The control sequences for carriage motion that 91.Nm 92understands and their decimal values are listed in the following 93table: 94.Pp 95.Bl -tag -width "carriage return" -compact 96.It ESC\-7 97reverse line feed (escape then 7) 98.It ESC\-8 99half reverse line feed (escape then 8) 100.It ESC\-9 101half forward line feed (escape then 9) 102.It backspace 103moves back one column (8); ignored in the first column 104.It carriage return 105(13) 106.It newline 107forward line feed (10); also does carriage return 108.It shift in 109shift to normal character set (15) 110.It shift out 111shift to alternate character set (14) 112.It space 113moves forward one column (32) 114.It tab 115moves forward to next tab stop (9) 116.It vertical tab 117reverse line feed (11) 118.El 119.Pp 120All unrecognized control characters and escape sequences are 121discarded. 122.Pp 123The 124.Nm 125utility keeps track of the character set as characters are read and makes 126sure the character set is correct when they are output. 127.Pp 128If the input attempts to back up to the last flushed line, 129.Nm 130will display a warning message. 131.Sh SEE ALSO 132.Xr expand 1 , 133.Xr nroff 1 , 134.Xr tbl 1 135.Sh STANDARDS 136The 137.Nm 138utility conforms to 139.St -susv2 . 140.Sh HISTORY 141A 142.Nm 143command 144appeared in 145.At v6 . 146