Man page of cat
Section: User Commands (1)
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cat - Concatenates or displays files
cat [-benrstuv] file...|-
command reads each specified file in sequence
and writes it to standard output.
Interfaces documented on this reference page conform to industry standards
cat: XPG4, XPG4-UNIX
Refer to the
reference page for more information
about industry standards and associated tags.
[Compaq] Omits line numbers from blank lines when
is specified. If you specify the
option is automatically invoked with it.
[Compaq] Same as the
option with a
(dollar sign) character displayed at the end of each line.
[Compaq] Displays output lines preceded by line numbers,
numbered sequentially from 1.
[Compaq] Replaces multiple consecutive empty lines with one
empty line, so that there is never more than one empty line between lines
[Compaq] Does not display a message if
cannot find an input file. (Silent option.)
[Compaq] Same as the
option, with the
tab character printed as
Does not buffer output. Writes bytes from the input file to
standard output without delay as each is read.
[Compaq] Displays nonprinting characters so that they are
The name of the file to be displayed.
If you do not specify a file or if you specify
(dash) instead of
reads from standard input. The
command accepts multiple
(dash) as a file argument.
command is frequently used with
symbol) to concatenate the specified files and write them to the specified
command is also used with
to append a file
to another file.
Do not redirect output to one of the input files using the
(redirection symbol). If you do this, you lose the original data
in the input file because the shell truncates it before
can read it. (See also the
The following exit values are returned:
An error occurred.
To display the file
If the file is longer than one screenful, it scrolls by too quickly
to read. To display a file one page at a time, use the
To concatenate several files, enter:
cat section1.1 section1.2 section1.3 > section1
This creates a file named
that is a copy
To suppress error messages about files that do not exist,
cat -s section2.1 section2.2 section2.3 > section2
does not exist, this command concatenates
section2.3. Note that the
message goes to standard error, so it does not appear in the output file.
The result is the same if you do not use the
displays the error message:
cat: cannot open section2.1
You may want to suppress this message with the
when you use the
command in shell procedures.
To append one file to the end of another, enter:
cat section1.4 >> section1
in this command specifies that a copy of
be added to the end of
If you want to replace the file, use a single
To add text to the end of a file, enter:
cat >> notes
Get milk on the way home
Get milk on the way home
is added to the end of
notes. With this syntax, the
not display a prompt; it waits for you to enter text. Press the End-of-File
key sequence (<Ctrl-d>
above) to indicate you are finished.
To concatenate several files with text entered from the keyboard,
cat section3.1 - section3.3 > section3
section3.1, text from the keyboard,
to create the file
To concatenate several files with output from another command,
ls | cat section4.1 - > section4
section4.1, and then the output of
command to the file
To get two pieces of input from the terminal (when standard
input is a terminal) with a single command invocation, enter:
cat start - middle - end > file1
If standard input is a regular file, however, the preceding command
is equivalent to the following:
cat start - middle /dev/null end > file1
This is because the entire contents of the file would be consumed by
the first time it saw
(dash) as a file
argument. An End-of-File condition would then be detected immediately when
(dash) appeared the second time.
The following environment variables affect the execution of
Provides a default value for the internationalization variables
that are unset or null. If
is unset or null, the corresponding value from the default locale is used.
If any of the internationalization variables contain an invalid setting, the
utility behaves as if none of the variables had been defined.
If set to a non-empty string value, overrides the values of
all the other internationalization variables.
Determines the locale for the interpretation of sequences
of bytes of text data as characters (for example, single-byte as opposed to
multibyte characters in arguments).
Determines the locale for the format and contents of diagnostic
messages written to standard error.
Determines the location of message catalogues for the processing
pr(1), Bourne shell
sh(1b), POSIX shell
- EXIT STATUS
- ENVIRONMENT VARIABLES
- SEE ALSO
This document was created by
using the manual pages.
Time: 02:43:03 GMT, October 02, 2010