cat - concatenate and print files
cat [-benstuv] [file ...]
The cat utility reads files sequentially, writing them to
output. The file operands are processed in command-line order. If file
is a single dash (`-') or absent, cat reads from the standard input.
The options are as follows:
-b Implies the -n option but doesn't count blank lines.
-e Implies the -v option and also prints a dollar sign
(`$') at the
end of each line.
-n Number the output lines, starting at 1.
-s Squeeze multiple adjacent empty lines, causing the
output to be
-t Implies the -v option and also prints tab characters
-u The output is guaranteed to be unbuffered (see setbuf(3)).
-v Displays non-printing characters so they are visible. Control
characters print as `^X' for control-X, with the exception of the
tab and EOL characters, which are displayed normally. The tab
character, control-I, can be made visible via the -t
DEL character (octal 0177) prints as `^?'. NonASCII characters
(with the high bit set) are printed as `M-' (for
by the character for the low 7 bits.
The cat utility exits 0 on success or >0 if an error occurred.
Print the contents of file1 to the standard output:
$ cat file1
Sequentially print the contents of file1 and file2 to the
truncating file3 if it already exists. See the manual page
shell (e.g., sh(1)) for more information on redirection.
$ cat file1 file2 > file3
Print the contents of file1, print data it receives from the
until it receives an EOF (`^D') character, print the
file2, read and output contents of the standard input again,
output the contents of file3. Note that if the standard input referred
to a file, the second dash on the command-line would have no
since the entire contents of the file would have already
been read and
printed by cat when it encountered the first `-' operand.
$ cat file1 - file2 - file3
head(1), less(1), more(1), pr(1), sh(1), tail(1), vis(1),
Rob Pike, "UNIX Style, or cat -v Considered Harmful", USENIX
Conference Proceedings, 1983.
The cat utility is compliant with the IEEE Std 1003.2-1992
The flags [-benstv] are extensions to the specification.
A cat utility appeared in Version 1 AT&T UNIX.
Because of the shell language mechanism used to perform output redirection,
the command cat file1 file2 > file1 will cause the
original data in
file1 to be destroyed!
OpenBSD 3.6 May 2, 1995
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