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3.1 cat: Concatenate and write files

cat copies each file (‘-’ means standard input), or standard input if none are given, to standard output. Synopsis:

     cat [option] [file]...

The program accepts the following options. Also see Common options.

Equivalent to -vET.
Number all nonempty output lines, starting with 1.
Equivalent to -vE.
Display a ‘$’ after the end of each line.
Number all output lines, starting with 1. This option is ignored if -b is in effect.
Suppress repeated adjacent empty lines; output just one empty line instead of several.
Equivalent to -vT.
Display TAB characters as ‘^I’.
Ignored; for POSIX compatibility.
Display control characters except for LFD and TAB using ‘^’ notation and precede characters that have the high bit set with ‘M-’.

On systems like MS-DOS that distinguish between text and binary files, cat normally reads and writes in binary mode. However, cat reads in text mode if one of the options -bensAE is used or if cat is reading from standard input and standard input is a terminal. Similarly, cat writes in text mode if one of the options -bensAE is used or if standard output is a terminal.

An exit status of zero indicates success, and a nonzero value indicates failure.


     # Output f's contents, then standard input, then g's contents.
     cat f - g
     # Copy standard input to standard output.