.\" Copyright (c) 1989, 1990 The Regents of the University of California. .\" All rights reserved. .\" .\" Redistribution and use in source and binary forms are permitted provided .\" that: (1) source distributions retain this entire copyright notice and .\" comment, and (2) distributions including binaries display the following .\" acknowledgement: ``This product includes software developed by the .\" University of California, Berkeley and its contributors'' in the .\" documentation or other materials provided with the distribution and in .\" all advertising materials mentioning features or use of this software. .\" Neither the name of the University nor the names of its contributors may .\" be used to endorse or promote products derived from this software without .\" specific prior written permission. .\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED .\" WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF .\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. .\" .\" @(#)cat.1 6.12 (Berkeley) 7/24/90 .\" .Dd July 24, 1990 .Dt CAT 1 .Os BSD 3 .Sh NAME .Nm cat .Nd concatenate and print files .Sh SYNOPSIS .Nm cat .Op Fl benstuv .Op Fl .Ar .Sh DESCRIPTION The .Nm cat utility reads files sequentially, writing them to the standard output. The .Ar file operands are processed in command line order. A single dash represents standard input. .Pp The options are as follows: .Tw Ds .Tp Fl b Implies the .Fl n option but doesn't number blank lines. .Tp Fl e Implies the .Fl v option, and displays a dollar sign (``$'') at the end of each line as well. .Tp Fl n Number the .Ar output lines, starting at 1. .Tp Fl s Squeeze multiple adjacent empty lines, causing the output to be single spaced. .Tp Fl t Implies the .Fl v option, and displays tab characters as ``^I'' as well. .Tp Fl u The .Fl u option guarantees that the output is unbuffered. .Tp Fl v Displays non-printing characters so they are visible. Control characters print line ``^X'' for control-X; the delete character (octal 0177) prints as ``^?''. Non-ascii characters (with the high bit set) are printed as `.`M-'' (for meta) followed by the character for the low 7 bits. .Tp .Pp .Nm Cat is useful for getting files into a pipe, for instance, to sort two files together, the command .Pp .Dl cat file1 file2 | sort > sfile .Pp reads the contents of file1 and file2 sequentially, pipes it all to sort and places the newly sorted data in file3. .Pp Because of the shell language mechanism used to perform output redirection, the command ``cat file1 file 2 > file1'' will cause .P original data in file1 to be destroyed! .Pp .Nm Cat The cat utility exits 0 on success, and >0 if an error occurs. .Sh SEE ALSO .Xr head 1 , .Xr more 1 , .Xr pr 1 , .Xr tail 1 .Pp Rob Pike, .Em UNIX Style, or cat -v Considered Harmful USENIX Summer Conference Proceedings, 1983. .Sh HISTORY The .Nm command appeared in Version 7 AT&T UNIX.