1 .\" Copyright (c) 1989, 1990, 1993
2 .\" The Regents of the University of California. All rights reserved.
4 .\" This code is derived from software contributed to Berkeley by
5 .\" the Institute of Electrical and Electronics Engineers, Inc.
7 .\" Redistribution and use in source and binary forms, with or without
8 .\" modification, are permitted provided that the following conditions
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.
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
35 .\" @(#)cat.1 8.3 (Berkeley) 5/2/95
36 .\" $FreeBSD: src/bin/cat/cat.1,v 1.10.2.9 2001/12/14 14:22:08 ru Exp $
38 .Dd September 15, 2001
43 .Nd concatenate and print files
51 utility reads files sequentially, writing them to the standard output.
54 operands are processed in command-line order.
61 reads from the standard input.
68 connects to it and then reads it until
72 domain binding capability available in
75 The options are as follows:
76 .Bl -tag -width indent
78 Number the non-blank output lines, starting at 1.
80 Display non-printing characters (see the
82 option), and display a dollar sign
84 at the end of each line.
86 Number the output lines, starting at 1.
88 Squeeze multiple adjacent empty lines, causing the output to be
91 Display non-printing characters (see the
93 option), and display tab characters as
98 option guarantees that the output is unbuffered.
100 Display non-printing characters so they are visible.
101 Control characters print as
103 for control-X; the delete
104 character (octal 0177) prints as
107 characters (with the high bit set) are printed as
109 (for meta) followed by the character for the low 7 bits.
115 .Bd -literal -offset indent
119 will print the contents of
121 to the standard output.
124 .Bd -literal -offset indent
125 .Ic cat file1 file2 > file3
128 will sequentially print the contents of
136 if it already exists.
137 See the manual page for your shell (i.e.,
139 for more information on redirection.
142 .Bd -literal -offset indent
143 .Ic cat file1 - file2 - file3
146 will print the contents of
148 print data it receives from the standard input until it receives an
151 character, print the contents of
153 read and output contents of the standard input again, then finally output
156 Note that if the standard input referred to a file, the second dash
157 on the command-line would have no effect, since the entire contents of the file
158 would have already been read and printed by
160 when it encountered the first
174 .%T "UNIX Style, or cat -v Considered Harmful"
175 .%J "USENIX Summer Conference Proceedings"
181 utility is compliant with the
187 are extensions to the specification.
194 designed and wrote the first man page.
195 It appears to have been
198 Because of the shell language mechanism used to perform output
199 redirection, the command
200 .Dq Li cat file1 file2 > file1
201 will cause the original data in file1 to be destroyed!