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Name

cat - concatenate and display files

Synopsis

cat [ -nbsuvet ] [file...]

Availability

SUNWcsu

Description

cat reads each file in sequence and writes it on the standard output. Thus:

example% cat file

prints file on your terminal, and:

example% cat file1 file2 >file3

concatenates file1 and file2, and writes the results in file3.

If no input file is given, cat reads from the standard input file.

Options

-n
Precede each line output with its line number.
-b
Number the lines, as -n, but omit the line numbers from blank lines.
-u
The output is not buffered. (The default is buffered output.)
-s
cat is silent about non-existent files.
-v
Non-printing characters (with the exception of tabs, new-lines and form-feeds) are printed visibly. ASCII control characters (octal 000 - 037) are printed as ^n, where n is the corresponding ASCII character in the range octal 100 - 137 (@, A, B, C, . . ., X, Y, Z, [, \, ], ^, and _); the DEL character (octal 0177) is printed ^?. Other non-printable characters are printed as M-x, where x is the ASCII character specified by the low-order seven bits.

When used with the -v option, the following options may be used:

-e
A $ character will be printed at the end of each line (prior to the new-line).
-t
Tabs will be printed as ^I’s and formfeeds to be printed as ^L’s.

The -e and -t options are ignored if the -v option is not specified.

Operands

The following operand is supported:
file
A path name of an input file. If no file is specified, the standard input is used. If file is ‘-’, cat will read from the standard input at that point in the sequence. cat will not close and reopen standard input when it is referenced in this way, but will accept multiple occurrences of ‘-’ as file.

Examples

    .
  1. The following command:

example% cat myfile

writes the contents of the file myfile to standard output.

    .
  1. The following command:

example% cat doc1 doc2 > doc.all

concatenates the files doc1 and doc2 and writes the result to doc.all.
    .
  1. The command:

example% cat start - middle - end > file

when standard input is a terminal, gets two arbitrary pieces of input from the terminal with a single invocation of cat. Note, however, that if standard input is a regular file, this would be equivalent to the command:

cat start - middle /dev/null end > file

because the entire contents of the file would be consumed by cat the first time ‘-’ was used as a file operand and an end-of-file condition would be detected immediately when ‘-’ was referenced the second time.

Environment

See environ(5) for descriptions of the following environment variables that affect the execution of cat: LC_CTYPE , LC_MESSAGES , and NLSPATH .

Exit Status

The following exit values are returned:
  1. All input files were output successfully.
    >0
    An error occurred.

    See Also

    touch(1) , environ(5)

    Notes

    Redirecting the output of cat onto one of the files being read will cause the loss of the data originally in the file being read. For example,

    example% cat filename1 filename2 >filename1

    causes the original data in filename1 to be lost.

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