Интерактивная система просмотра системных руководств (man-ов)
cat (1)
cat (1) ( Solaris man: Команды и прикладные программы пользовательского уровня )
>> cat (1) ( FreeBSD man: Команды и прикладные программы пользовательского уровня )
cat (1) ( Русские man: Команды и прикладные программы пользовательского уровня )
cat (1) ( Linux man: Команды и прикладные программы пользовательского уровня )
cat (1) ( POSIX man: Команды и прикладные программы пользовательского уровня )
cat (8) ( Русские man: Команды системного администрирования )
BSD mandoc
NAME
cat
- concatenate and print files
SYNOPSIS
[-benstuv
]
[file ...
]
DESCRIPTION
The
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,
reads from the standard input.
If
file
is a
UNIX
domain socket,
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
Ex -std
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 contents 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
when it encountered the first
`-
'
operand.
Rob Pike
"UNIX Style, or cat -v Considered Harmful""USENIX Summer Conference Proceedings"
1983
STANDARDS
The
utility is compliant with the
St -p1003.2-92
specification.
The flags
[-benstv
]
are extensions to the specification.
HISTORY
A
utility appeared in
AT&T System
v1 .
An 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
utility does not recognize multibyte characters when the
-t
or
-v
option is in effect.
