Concatenates or displays files.
The cat command reads each File parameter in sequence and writes it to standard output. If you do not specify a file name, the cat command reads from standard input. You can also specify a file name of - (dash) for standard input.
|-b||Omits line numbers from blank lines, when specified with the -n flag.|
|-e||Displays a $ (dollar sign) at the end of each line, when specified with the -v flag.|
|-n||Displays output lines preceded by line numbers, numbered sequentially from 1.|
|-q||Does not display a message if the cat command cannot find an input file. This flag is identical to the -s flag.|
|-r||Replaces multiple consecutive empty lines with one empty line. This flag is identical to the -S flag.|
|-s||Does not display a message if the cat command cannot
find an input file. This flag is identical to the -q flag.
Note: Previously, the -s flag handled tasks now assigned to the -S flag.
|-S||Replaces multiple consecutive empty lines with one empty line. This flag is identical to the -r flag.|
|-t||Displays tab characters as ^I if specified with the -v flag.|
|-u||Does not buffer output. The default is buffered output.|
Displays nonprinting characters as visible characters,
with the exception of tabs, new-lines, and form-feeds. ASCII control
characters (octal 000–037) are printed as
When used with the -v option, the following options may be used:
The -e and -t options are ignored if the -v option is not specified.
|-||Allows standard input to the cat command.|
|Z||Dumps the contents of encrypted files in encrypted format. Access keys to the encrypted file are not required to do cat -Z on the file.|
This command returns the following exit values:
|0||All input files were output successfully.|
|>0||An error occurred.|
- To display a file at the workstation, enter:
This command displays the data in the notes file. If the file is more than one less than the number of available display lines, some of the file scrolls off the screen. To list a file one page at a time, use the pg command.
- To concatenate several files, enter:
This command creates a file named section1 that is a copy of section1.1 followed by section1.2 and section1.3.
cat section1.1 section1.2 section1.3 >section1
- To suppress error messages about files that do not exist, enter:
cat -q section2.1 section2.2 section2.3 >section2If section2.1 does not exist, this command concatenates section2.2 and section2.3. The result is the same if you do not use the -q flag, except that the cat command displays the error message:
You may want to suppress this message with the -q flag when you use the cat command in shell procedures.
cat: cannot open section2.1
- To append one file to the end of another, enter:
The >> (two carets) appends a copy of section1.4 to the end of section1. If you want to replace the file, use the > (caret).
cat section1.4 >> section1
- To add text to the end of a file, enter:
This command adds Get milk on the way home to the end of the file called notes. The cat command does not prompt; it waits for you to enter text. Press the Ctrl-D key sequence to indicate you are finished.
cat >>notes Get milk on the way home Ctrl-D
- To concatenate several files with text entered from the keyboard,
This command concatenates the file section3.1 with text from the keyboard (indicated by the minus sign), and the file section3.3, then directs the output into the file called
cat section3.1 - section3.3 >section3
|/usr/bin/cat||Contains the cat command.|