cat(1) [mojave man page]
CAT(1) BSD General Commands Manual CAT(1) NAME
cat -- concatenate and print files SYNOPSIS
cat [-benstuv] [file ...] DESCRIPTION
The cat utility reads files sequentially, writing them to the standard output. The file operands are processed in command-line order. If file is a single dash ('-') or absent, cat reads from the standard input. If file is a UNIX domain socket, cat connects to it and then reads it until EOF. This complements the UNIX domain binding capability available in inetd(8). The options are as follows: -b Number the non-blank output lines, starting at 1. -e Display non-printing characters (see the -v option), and display a dollar sign ('$') at the end of each line. -n Number the output lines, starting at 1. -s Squeeze multiple adjacent empty lines, causing the output to be single spaced. -t Display non-printing characters (see the -v option), and display tab characters as '^I'. -u Disable output buffering. -v Display non-printing characters so they are visible. Control characters print as '^X' for control-X; the delete character (octal 0177) prints as '^?'. Non-ASCII characters (with the high bit set) are printed as 'M-' (for meta) followed by the character for the low 7 bits. EXIT STATUS
The cat utility exits 0 on success, and >0 if an error occurs. EXAMPLES
The command: cat file1 will print the contents of file1 to the standard output. The command: cat file1 file2 > file3 will sequentially print the contents of file1 and file2 to the file file3, truncating file3 if it already exists. See the manual page for your shell (i.e., sh(1)) for more information on redirection. The command: cat file1 - file2 - file3 will print the contents of file1, print data it receives from the standard input until it receives an EOF ('^D') character, print the con- tents of file2, read and output contents of the standard input again, then finally output the contents of file3. Note that if the standard input referred to a file, the second dash on the command-line would have no effect, since the entire contents of the file would have already been read and printed by cat when it encountered the first '-' operand. SEE ALSO
head(1), more(1), pr(1), sh(1), tail(1), vis(1), zcat(1), setbuf(3) Rob Pike, "UNIX Style, or cat -v Considered Harmful", USENIX Summer Conference Proceedings, 1983. STANDARDS
The cat utility is compliant with the IEEE Std 1003.2-1992 (``POSIX.2'') specification. The flags [-benstv] are extensions to the specification. HISTORY
A cat utility appeared in Version 1 AT&T UNIX. Dennis Ritchie designed and wrote the first man page. It appears to have been cat(1). BUGS
Because of the shell language mechanism used to perform output redirection, the command ``cat file1 file2 > file1'' will cause the original data in file1 to be destroyed! The cat utility does not recognize multibyte characters when the -t or -v option is in effect. BSD
March 21, 2004 BSD
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cat(1) User Commands cat(1) NAME
cat - concatenate and display files SYNOPSIS
cat [-nbsuvet] [file...] DESCRIPTION
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 standard input file. OPTIONS
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 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. USAGE
See largefile(5) for the description of the behavior of cat when encountering files greater than or equal to 2 Gbyte ( 2**31 bytes). EXAMPLES
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 to doc.all. Example 3: Concatenating two arbitrary pieces of input with a single invocation 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 VARIABLES
See environ(5) for descriptions of the following environment variables that affect the execution of cat: LANG, LC_ALL, LC_CTYPE, LC_MES- SAGES, and NLSPATH. EXIT STATUS
The following exit values are returned: 0 All input files were output successfully. >0 An error occurred. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWcsu | +-----------------------------+-----------------------------+ |CSI |enabled | +-----------------------------+-----------------------------+ |Interface Stability |Standard | +-----------------------------+-----------------------------+ SEE ALSO
touch(1), attributes(5), environ(5), largefile(5), standards(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 exam- ple, example% cat filename1 filename2 >filename1 causes the original data in filename1 to be lost. SunOS 5.10 1 Feb 1995 cat(1)