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 2. Common options.

`-A'

`--show-all'

Equivalent to `-vET'.

`-B'

`--binary'

On MS-DOS and MS-Windows only, read and write the files in binary mode. By default, cat on MS-DOS/MS-Windows uses binary mode only when standard output is redirected to a file or a pipe; this option overrides that. Binary file I/O is used so that the files retain their format (Unix text as opposed to DOS text and binary), because cat is frequently used as a file-copying program. Some options (see below) cause cat read and write files in text mode because then the original file contents aren't important (e.g., when lines are numbered by cat, or when line endings should be marked). This is so these options work as DOS/Windows users would expect; for example, DOS-style text files have their lines end with the CR-LF pair of characters which won't be processed as an empty line by `-b' unless the file is read in text mode.

`-b'

`--number-nonblank'

Number all nonblank output lines, starting with 1. On MS-DOS and MS-Windows, this option causes cat to read and write files in text mode.

`-e'

Equivalent to `-vE'.

`-E'

`--show-ends'

Display a `$' after the end of each line. On MS-DOS and MS-Windows, this option causes cat to read and write files in text mode.

`-n'

`--number'

Number all output lines, starting with 1. On MS-DOS and MS-Windows, this option causes cat to read and write files in text mode.

`-s'

`--squeeze-blank'

Replace multiple adjacent blank lines with a single blank line. On MS-DOS and MS-Windows, this option causes cat to read and write files in text mode.

`-t'

Equivalent to `-vT'.

`-T'

`--show-tabs'

Display TAB characters as `^I'.

`-u'

Ignored; for Unix compatibility.

`-v'

`--show-nonprinting'

Display control characters except for LFD and TAB using `^' notation and precede characters that have the high bit set with `M-'. On MS-DOS and MS-Windows, this option causes cat to read files and standard input in DOS binary mode, so the CR characters at the end of each line are also visible.