Linux / Unix Command: test

内容来源 ： http://linux.about.com/library/cmd/blcmdl1_test.htm

NAME

test - check file types and compare values 
SYNOPSIS

test EXPRESSION
[ EXPRESSION ]
test OPTION 
DESCRIPTION

Exit with the status determined by EXPRESSION.

--help
display this help and exit
--version
output version information and exit
EXPRESSION is true or false and sets exit status. It is one of:

( EXPRESSION )
EXPRESSION is true
! EXPRESSION
EXPRESSION is false
EXPRESSION1 -a EXPRESSION2
both EXPRESSION1 and EXPRESSION2 are true
EXPRESSION1 -o EXPRESSION2
either EXPRESSION1 or EXPRESSION2 is true
[-n] STRING
the length of STRING is nonzero
-z STRING
the length of STRING is zero
STRING1 = STRING2
the strings are equal
STRING1 != STRING2
the strings are not equal
INTEGER1 -eq INTEGER2
INTEGER1 is equal to INTEGER2
INTEGER1 -ge INTEGER2
INTEGER1 is greater than or equal to INTEGER2
INTEGER1 -gt INTEGER2
INTEGER1 is greater than INTEGER2
INTEGER1 -le INTEGER2
INTEGER1 is less than or equal to INTEGER2
INTEGER1 -lt INTEGER2
INTEGER1 is less than INTEGER2
INTEGER1 -ne INTEGER2
INTEGER1 is not equal to INTEGER2
FILE1 -ef FILE2
FILE1 and FILE2 have the same device and inode numbers
FILE1 -nt FILE2
FILE1 is newer (modification date) than FILE2
FILE1 -ot FILE2
FILE1 is older than FILE2
-b FILE
FILE exists and is block special
-c FILE
FILE exists and is character special
-d FILE
FILE exists and is a directory
-e FILE
FILE exists
-f FILE
FILE exists and is a regular file
-g FILE
FILE exists and is set-group-ID
-h FILE
FILE exists and is a symbolic link (same as -L)
-G FILE
FILE exists and is owned by the effective group ID
-k FILE
FILE exists and has its sticky bit set
-L FILE
FILE exists and is a symbolic link (same as -h)
-O FILE
FILE exists and is owned by the effective user ID
-p FILE
FILE exists and is a named pipe
-r FILE
FILE exists and is readable
-s FILE
FILE exists and has a size greater than zero
-S FILE
FILE exists and is a socket
-t [FD]
file descriptor FD (stdout by default) is opened on a terminal
-u FILE
FILE exists and its set-user-ID bit is set
-w FILE
FILE exists and is writable
-x FILE
FILE exists and is executable
Beware that parentheses need to be escaped (e.g., by backslashes) for shells. INTEGER may also be -l STRING, which evaluates to the length of STRING. 

SEE ALSO

The full documentation for test is maintained as a Texinfo manual. If the info and test programs are properly installed at your site, the command
info test
should give you access to the complete manual.