cat - concatenate and display files
cat [-nbsuvet] [file...]
The cat utility 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 stan-
dard input file.
The following options are supported:
-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
-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
-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
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.
See largefile(5) for the description of the behavior of cat
when encountering files greater than or equal to 2 Gbyte ( 2
Example 1: Concatenating a file
The following command:
example% cat myfile
writes the contents of the file myfile to standard output.
Example 2: Concatenating two files into one
The following command:
example% cat doc1 doc2 > doc.all
concatenates the files doc1 and doc2 and writes the result
Example 3: Concatenating two arbitrary pieces of input with
a single invocation
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.
See environ(5) for descriptions of the following environment
variables that affect the execution of cat: LANG, LC_ALL,
LC_CTYPE, LC_MESSAGES, and NLSPATH.
The following exit values are returned:
0 All input files were output successfully.
>0 An error occurred.
See attributes(5) for descriptions of the following attri-
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
| Availability | SUNWcsu |
| CSI | enabled |
| Interface Stability | Standard |
touch(1), attributes(5), environ(5), largefile(5), stan-
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.
Man(1) output converted with