|HP-UX Reference > C
HP-UX 11i Version 3: February 2007
cat — concatenate, copy, and print files
cat reads each file in sequence and writes it on the standard output. Thus:
prints file on the default standard output device;
cat file1 file2 > file3
concatenates file1 and file2, and places the result in file3.
If - is appears as a file argument, cat uses standard input. To combine standard input and other files, use a combination of - and file arguments.
cat recognizes the following options:
LANG provides a default value for the internationalization variables that are unset or null. If LANG is unset or null, the default value of "C" (see lang(5)) is used. If any of the internationalization variables contains an invalid setting, cat will behave as if all internationalization variables are set to "C". See environ(5).
LC_ALL If set to a non-empty string value, overrides the values of all the other internationalization variables.
LC_CTYPE determines the interpretation of text as single and/or multi-byte characters, the classification of characters as printable, and the characters matched by character class expressions in regular expressions.
LC_MESSAGES determines the locale that should be used to affect the format and contents of diagnostic messages written to standard error and informative messages written to standard output.
NLSPATH determines the location of message catalogues for the processing of LC_MESSAGES.
To create a zero-length file, use any of the following:
cat /dev/null > file cp /dev/null file touch file
The following prints ^I for all the occurrences of tab character in file1
cat -t file1
To suppress error messages about files that do not exist, use:
cat -s file1 file2 file3 > file
If file2 does not exist, the above command concatenates file1 and file3 without reporting the error on file2. The result is the same if -s option is not used, except that cat displays the error message.
To view non-printable characters in file2, use:
cat -v file2
Command formats such as
cat file1 file2 > file1
overwrites the data in file1 before the concatenation begins, thus destroying the file. Therefore, be careful when using shell special characters.