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OpenDarwin 7.2.1 - man page for cat (opendarwin section 1)

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CAT(1)				   BSD General Commands Manual				   CAT(1)

NAME
     cat -- concatenate and print files

SYNOPSIS
     cat [-benstuv] [file ...]

DESCRIPTION
     The cat utility reads files sequentially, writing them to the standard output.  The file op-
     erands are processed in command-line order.  If file is a single dash ('-') or absent, cat
     reads from the standard input.  If file is a UNIX domain socket, cat connects to it and then
     reads it until EOF.  This complements the UNIX domain binding capability available in
     inetd(8).

     The options are as follows:

     -b      Number the non-blank output lines, starting at 1.

     -e      Display non-printing characters (see the -v option), and display 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 single spaced.

     -t      Display non-printing characters (see the -v option), and display tab characters as
	     '^I'.

     -u      The -u option guarantees that the output is unbuffered.

     -v      Display non-printing characters so they are visible.  Control characters print as
	     '^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.

DIAGNOSTICS
     The cat utility exits 0 on success, and >0 if an error occurs.

EXAMPLES
     The command:

	   cat file1

     will print the contents of file1 to the standard output.

     The command:

	   cat file1 file2 > file3

     will sequentially print the contents of file1 and file2 to the file file3, truncating file3
     if it already exists.  See the manual page for your shell (i.e., sh(1)) for more information
     on redirection.

     The command:

	   cat file1 - file2 - file3

     will print the contents of file1, print data it receives from the standard input until it
     receives an EOF ('^D') character, print the contents of file2, read and output contents of
     the standard input again, then finally output the contents of file3.  Note that if the stan-
     dard input referred to a file, the second dash on the command-line would have no effect,
     since the entire contents of the file would have already been read and printed by cat when
     it encountered the first '-' operand.

SEE ALSO
     head(1), more(1), pr(1), sh(1), tail(1), vis(1), zcat(1), setbuf(3)

     Rob Pike, "UNIX Style, or cat -v Considered Harmful", USENIX Summer Conference Proceedings,
     1983.

STANDARDS
     The cat utility is compliant with the IEEE Std 1003.2-1992 (``POSIX.2'') specification.

     The flags [-benstv] are extensions to the specification.

HISTORY
     A cat utility appeared in Version 1 AT&T UNIX.  Dennis Ritchie designed and wrote the first
     man page.	It appears to have been cat(1).

BUGS
     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!

BSD					September 15, 2001				      BSD
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