4.1cBSD/usr/man/man1/cat.1

.TH CAT 1 "18 January 1983"
.SH NAME
cat \- catenate and print
.SH SYNOPSIS
.B cat
[
.B \-u
] [
.B \-n
] [
.B \-s
] [
.B \-v
]
file ...
.br
.SH DESCRIPTION
.I Cat
reads each
.I file
in sequence and displays it on the standard output.  Thus
.PP
.ti+15n
cat file
.PP
displays the file on the standard output, and
.PP
.ti+15n
cat file1 file2 >file3
.PP
concatenates the first two files and places the result on the third.
.PP
If no input file is given, or if the argument `\-' is encountered,
.I cat
reads from the standard input file.
Output is buffered in 1024-byte blocks unless the standard
output is a terminal, in which case it is line buffered.  The
.B \-u
option makes the output completely unbuffered.
.PP
The
.B \-n
option displays the output lines preceded by lines numbers, numbered
sequentially from 1.  Specifying the 
.B \-b
option with the
.B \-n
option omits the line numbers from blank lines.
.PP
The
.B \-s
option crushes out multiple adjacent empty lines so that the
output is displayed single spaced.
.PP
The
.B \-v
option displays non-printing characters so that they are visible.
Control characters print like ^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 of the low 7 bits.  A
.B \-e
option may be given with the
.B \-v
option, which displays a `$' character at the end of each line.
Specifying the 
.B \-t
option with the
.B \-v
option displays tab characters as ^I.
.PP
.SH "SEE ALSO"
cp(1), ex(1), more(1), pr(1), tail(1)
.SH MESSAGES
.IP "cat: can't open \fIfilename\fP" 10
.br
\fICat\fP couldn't access the file specified by \fIfilename\fP.  Check
the spelling of the filename, or check that the permissions allow read access.
.IP "cat: input \fIfilename\fP is output" 10
.br
\fICat\fP displays this message if you try to redirect its output to a
file which was one of the input files \(em in other words, \fIcat\fP
won't overwrite one of its input files.
.IP "cat: output write error" 10
.br
\fICat\fP has encountered some problem while trying to write the output
file.
.SH BUGS
Beware of `cat a b >a' and `cat a b >b', which destroy
the input files before reading them.