shell之test

NAME
       test - check file types and compare values


SYNOPSIS
       test EXPRESSION
       test


       [ EXPRESSION ]
       [ ]
       [ OPTION


DESCRIPTION
       Exit with the status determined by EXPRESSION.


       --help display this help and exit


       --version
              output version information and exit


       An omitted EXPRESSION defaults to false.  Otherwise, 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


       STRING equivalent to -n STRING


       -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


       -G FILE
              FILE exists and is owned by the effective group ID


       -h FILE
              FILE exists and is a symbolic link (same as -L)


       -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 read permission is granted


       -s FILE
              FILE exists and has a size greater than zero


       -S FILE
              FILE exists and is a socket


       -t FD  file descriptor FD is opened on a terminal


       -u FILE
              FILE exists and its set-user-ID bit is set


       -w FILE
              FILE exists and write permission is granted


       -x FILE
              FILE exists and execute (or search) permission is granted


       Except  for  -h  and  -L,  all FILE-related tests dereference symbolic links.  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.


       NOTE: [ honors the --help and --version options, but test does not.  test treats each of those as it treats any other nonempty STRING.


       NOTE: your shell may have its own version of test and/or [, which usually supersedes the version described here.  Please refer to your shell's documentation for details about the options it sup鈥?
       ports.


AUTHOR
       Written by Kevin Braunsdorf and Matthew Bradburn.


REPORTING BUGS
       Report test bugs to [e-mail]
       GNU coreutils home page: <http://www.gnu.org/software/coreutils/>
       General help using GNU software: <http://www.gnu.org/gethelp/>
       Report test translation bugs to <http://translationproject.org/team/>


COPYRIGHT
       Copyright 漏 2013 Free Software Foundation, Inc.  License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
       This is free software: you are free to change and redistribute it.  There is NO WARRANTY, to the extent permitted by law.


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 coreutils 'test invocation'


       should give you access to the complete manual.






GNU coreutils 8.21                                                                              March 2014                                                                                        TEST(1)