cat(1) [osx 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
/usr/bin/cat /usr/bin/cat [-nbsuvet] [file...] ksh93 cat [-bdenstuvABDEST] [file...] DESCRIPTION
/usr/bin/cat 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. ksh93 The cat built-in in ksh93 is associated with the /bin and /usr/bin paths. It is invoked when cat is executed without a pathname prefix and the pathname search finds a /bin/cat or /usr/bin/cat executable. cat copies each file in sequence to the standard output. If no file is specified, or if the file is -, cat copies from standard input starting at the current location. OPTIONS
/usr/bin/cat The following options are supported by /usr/bin/cat: -b Number the lines, as -n, but omit the line numbers from blank lines. -n Precede each line output with its line number. -s cat is silent about non-existent files. -u The output is not buffered. Buffered output is the default. -v Non-printing characters, with the exception of tabs, NEWLINEs 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 can be used: -e A $ character is printed at the end of each line, prior to the NEWLINE. -t Tabs are printed as ^Is and form feeds to be printed as ^Ls. The -e and -t options are ignored if the -v option is not specified. ksh93 ksh93 cat supports the following options: -b --number-nonblank Number lines as with -n but omit line numbers from blank lines. -d --dos-input Open input files in text mode. Removes RETURNs in front of NEWLINEs on some systems. -e Equivalent to -vE. -n --number Insert a line number at the beginning of each line. -s Equivalent to -S for att universe and -B otherwise. -t Equivalent to -vT. -u --unbuffer Do not delay the output by buffering. -v --show-nonprinting Cause non-printing characters (with the exception of TABs, NEWLINEs, and form feeds) to be output as printable character sequences. ASCII control characters are printed as ^n, where n is the corresponding ASCII character in the range octal 100-137. The DEL character (octal 0177) is copied as ^?. Other non-printable characters are copied as M-x where x is the ASCII character specified by the low-order seven bits. Multi-byte characters in the current locale are treated as printable characters. -A --show-all Equivalent to -vET. -B --squeeze-blank Replace multiple adjacent NEWLINE characters with one NEWLINE. -D --dos-output Open output files in text mode. Insert RETURNs in front of NEWLINEs on some systems. -E --show-ends Insert a $ before each NEWLINE. -S --silent cat is silent about non-existent files. -T --show-blank Copies TABs as ^I and form feeds as ^L. 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 reads from the standard input at that point in the sequence. cat does not close and reopen standard input when it is referenced in this way, but accepts 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 writes the contents of the file myfile to standard output: example% cat myfile Example 2 Concatenating Two files into One The following command concatenates the files doc1 and doc2 and writes the result to doc.all. example% cat doc1 doc2 > doc.all Example 3 Concatenating Two Arbitrary Pieces of Input with a Single Invocation When standard input is a terminal, the following command gets two arbitrary pieces of input from the terminal with a single invocation of cat: 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. If standard input is a regular file, example% cat start - middle - end > file would be equivalent to the following 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: /usr/bin/cat +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWcsu | +-----------------------------+-----------------------------+ |CSI |Enabled | +-----------------------------+-----------------------------+ |Interface Stability |Committed | +-----------------------------+-----------------------------+ |Standard |See standards(5). | +-----------------------------+-----------------------------+ ksh93 +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWcsu | +-----------------------------+-----------------------------+ |Interface Stability |See below. | +-----------------------------+-----------------------------+ The ksh93 built-in binding to /bin and /usr/bin is Volatile. The built-in interfaces are Uncommitted. 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 causes 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. SunOS 5.11 8 Apr 2008 cat(1)