NetBSD/bin/cat/cat.1

.\"	$NetBSD: cat.1,v 1.16 1999/03/22 18:30:42 garbled Exp $
.\"
.\" Copyright (c) 1989, 1990, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" the Institute of Electrical and Electronics Engineers, Inc.
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.\" modification, are permitted provided that the following conditions
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.\"    notice, this list of conditions and the following disclaimer in the
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.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
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.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
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.\"     @(#)cat.1	8.3 (Berkeley) 5/2/95
.\"
.Dd May 2, 1995
.Dt CAT 1
.Os
.Sh NAME
.Nm cat
.Nd concatenate and print files
.Sh SYNOPSIS
.Nm
.Op Fl benstuv
.Op Fl
.Op Ar
.Sh DESCRIPTION
The
.Nm
utility reads files sequentially, writing them to the standard output.
The
.Ar file
operands are processed in command line order.
A single dash represents the standard input.
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl b
Implies the
.Fl n
option but doesn't number blank lines.
.It Fl e
Implies the
.Fl v
option, and displays a dollar sign
.Pq Ql \&$
at the end of each line
as well.
.It Fl n
Number the output lines, starting at 1.
.It Fl s
Squeeze multiple adjacent empty lines, causing the output to be
single spaced.
.It Fl t
Implies the
.Fl v
option, and displays tab characters as
.Ql ^I
as well.
.It Fl u
The
.Fl u
option guarantees that the output is unbuffered.
.It Fl v
Displays non-printing characters so they are visible.
Control characters print as
.Ql ^X
for control-X; the delete
character (octal 0177) prints as
.Ql ^?
Non-ascii characters (with the high bit set) are printed as
.Ql M-
(for meta) followed by the character for the low 7 bits.
.El
.Pp
The
.Nm
utility exits 0 on success, and >0 if an error occurs.
.Sh BUGS
Because of the shell language mechanism used to perform output
redirection, the command
.Dq Li cat file1 file2 > file1
will cause the original data in file1 to be destroyed!
.Sh SEE ALSO
.Xr head 1 ,
.Xr more 1 ,
.Xr pr 1 ,
.Xr tail 1 ,
.Xr vis 1
.Rs
.%A Rob Pike
.%T "UNIX Style, or cat -v Considered Harmful"
.%J "USENIX Summer Conference Proceedings"
.%D 1983
.Re
.Sh HISTORY
A
.Nm
utility appeared in Version 1 AT&T UNIX. 
Dennis Ritchie designed and wrote the first man page. 
It appears to have been
.Xr cat 1 .
.Sh STANDARDS
The
.Nm
utility is expected to conform to the
.St -p1003.2-92
specification.
.Pp
The flags
.Op Fl benstv
are extensions to the specification.