1.\" Copyright (c) 1989, 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.\" the Institute of Electrical and Electronics Engineers, Inc. 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.\" @(#)cat.1 8.3 (Berkeley) 5/2/95 36.\" $FreeBSD$ 37.\" 38.Dd September 15, 2001 39.Dt CAT 1 40.Os 41.Sh NAME 42.Nm cat 43.Nd concatenate and print files 44.Sh SYNOPSIS 45.Nm 46.Op Fl benstuv 47.Op Ar 48.Sh DESCRIPTION 49The 50.Nm 51utility reads files sequentially, writing them to the standard output. 52The 53.Ar file 54operands are processed in command-line order. 55If 56.Ar file 57is a single dash 58.Pq Sq \&- 59or absent, 60.Nm 61reads from the standard input. 62If 63.Ar file 64is a 65.Ux 66domain socket, 67.Nm 68connects to it and then reads it until 69.Dv EOF . 70This complements the 71.Ux 72domain binding capability available in 73.Xr inetd 8 . 74.Pp 75The options are as follows: 76.Bl -tag -width indent 77.It Fl b 78Number the non-blank output lines, starting at 1. 79.It Fl e 80Display non-printing characters (see the 81.Fl v 82option), and display a dollar sign 83.Pq Ql \&$ 84at the end of each line. 85.It Fl n 86Number the output lines, starting at 1. 87.It Fl s 88Squeeze multiple adjacent empty lines, causing the output to be 89single spaced. 90.It Fl t 91Display non-printing characters (see the 92.Fl v 93option), and display tab characters as 94.Ql ^I . 95.It Fl u 96The 97.Fl u 98option guarantees that the output is unbuffered. 99.It Fl v 100Display non-printing characters so they are visible. 101Control characters print as 102.Ql ^X 103for control-X; the delete 104character (octal 0177) prints as 105.Ql ^? . 106.Pf Non- Tn ASCII 107characters (with the high bit set) are printed as 108.Ql M- 109(for meta) followed by the character for the low 7 bits. 110.El 111.Sh DIAGNOSTICS 112.Ex -std 113.Sh EXAMPLES 114The command: 115.Bd -literal -offset indent 116.Ic cat file1 117.Ed 118.Pp 119will print the contents of 120.Ar file1 121to the standard output. 122.Pp 123The command: 124.Bd -literal -offset indent 125.Ic cat file1 file2 > file3 126.Ed 127.Pp 128will sequentially print the contents of 129.Ar file1 130and 131.Ar file2 132to the file 133.Ar file3 , 134truncating 135.Ar file3 136if it already exists. 137See the manual page for your shell (i.e., 138.Xr sh 1 ) 139for more information on redirection. 140.Pp 141The command: 142.Bd -literal -offset indent 143.Ic cat file1 - file2 - file3 144.Ed 145.Pp 146will print the contents of 147.Ar file1 , 148print data it receives from the standard input until it receives an 149.Dv EOF 150.Pq Sq ^D 151character, print the contents of 152.Ar file2 , 153read and output contents of the standard input again, then finally output 154the contents of 155.Ar file3 . 156Note that if the standard input referred to a file, the second dash 157on the command-line would have no effect, since the entire contents of the file 158would have already been read and printed by 159.Nm 160when it encountered the first 161.Ql \&- 162operand. 163.Sh SEE ALSO 164.Xr head 1 , 165.Xr more 1 , 166.Xr pr 1 , 167.Xr sh 1 , 168.Xr tail 1 , 169.Xr vis 1 , 170.Xr zcat 1 , 171.Xr setbuf 3 172.Rs 173.%A Rob Pike 174.%T "UNIX Style, or cat -v Considered Harmful" 175.%J "USENIX Summer Conference Proceedings" 176.%D 1983 177.Re 178.Sh STANDARDS 179The 180.Nm 181utility is compliant with the 182.St -p1003.2-92 183specification. 184.Pp 185The flags 186.Op Fl benstv 187are extensions to the specification. 188.Sh HISTORY 189A 190.Nm 191utility appeared in 192.At v1 . 193.An Dennis Ritchie 194designed and wrote the first man page. 195It appears to have been 196.Xr cat 1 . 197.Sh BUGS 198Because of the shell language mechanism used to perform output 199redirection, the command 200.Dq Li cat file1 file2 > file1 201will cause the original data in file1 to be destroyed! 202