TEST(1) 						    BSD General Commands Manual 						   TEST(1)

NAME

     test, [ -- condition evaluation utility

SYNOPSIS

     test expression
     [ expression ]

DESCRIPTION

     The test utility evaluates the expression and, if it evaluates to true, returns a zero (true) exit status; otherwise it returns 1 (false).
     If there is no expression, test also returns 1 (false).

     All operators and flags are separate arguments to the test utility.

     The following primaries are used to construct expression:

     -b file	   True if file exists and is a block special file.

     -c file	   True if file exists and is a character special file.

     -d file	   True if file exists and is a directory.

     -e file	   True if file exists (regardless of type).

     -f file	   True if file exists and is a regular file.

     -g file	   True if file exists and its set group ID flag is set.

     -h file	   True if file exists and is a symbolic link.	This operator is retained for compatibility with previous versions of this pro-
		   gram.  Do not rely on its existence; use -L instead.

     -k file	   True if file exists and its sticky bit is set.

     -n string	   True if the length of string is nonzero.

     -p file	   True if file is a named pipe (FIFO).

     -r file	   True if file exists and is readable.

     -s file	   True if file exists and has a size greater than zero.

     -t file_descriptor
		   True if the file whose file descriptor number is file_descriptor is open and is associated with a terminal.

     -u file	   True if file exists and its set user ID flag is set.

     -w file	   True if file exists and is writable.  True indicates only that the write flag is on.  The file is not writable on a read-only
		   file system even if this test indicates true.

     -x file	   True if file exists and is executable.  True indicates only that the execute flag is on.  If file is a directory, true indi-
		   cates that file can be searched.

     -z string	   True if the length of string is zero.

     -L file	   True if file exists and is a symbolic link.

     -O file	   True if file exists and its owner matches the effective user id of this process.

     -G file	   True if file exists and its group matches the effective group id of this process.

     -S file	   True if file exists and is a socket.

     file1 -nt file2
		   True if file1 exists and is newer than file2.

     file1 -ot file2
		   True if file1 exists and is older than file2.

     file1 -ef file2
		   True if file1 and file2 exist and refer to the same file.

     string	   True if string is not the null string.

     s1 = s2	   True if the strings s1 and s2 are identical.

     s1 != s2	   True if the strings s1 and s2 are not identical.

     s1 < s2	   True if string s1 comes before s2 based on the binary value of their characters.

     s1 > s2	   True if string s1 comes after s2 based on the binary value of their characters.

     n1 -eq n2	   True if the integers n1 and n2 are algebraically equal.

     n1 -ne n2	   True if the integers n1 and n2 are not algebraically equal.

     n1 -gt n2	   True if the integer n1 is algebraically greater than the integer n2.

     n1 -ge n2	   True if the integer n1 is algebraically greater than or equal to the integer n2.

     n1 -lt n2	   True if the integer n1 is algebraically less than the integer n2.

     n1 -le n2	   True if the integer n1 is algebraically less than or equal to the integer n2.

     If file is a symbolic link, test will fully dereference it and then evaluate the expression against the file referenced, except for the -h
     and -L primaries.

     These primaries can be combined with the following operators:

     ! expression  True if expression is false.

     expression1 -a expression2
		   True if both expression1 and expression2 are true.

     expression1 -o expression2
		   True if either expression1 or expression2 are true.

     ( expression )
		   True if expression is true.

     The -a operator has higher precedence than the -o operator.

     Some shells may provide a builtin test command which is similar or identical to this utility.  Consult the builtin(1) manual page.

GRAMMAR AMBIGUITY

     The test grammar is inherently ambiguous.	In order to assure a degree of consistency, the cases described in the IEEE Std 1003.2
     (``POSIX.2''), section D11.2/4.62.4, standard are evaluated consistently according to the rules specified in the standards document.  All
     other cases are subject to the ambiguity in the command semantics.

     In particular, only expressions containing -a, -o, ( or ) can be ambiguous.

EXIT STATUS

     The test utility exits with one of the following values:

     0	     expression evaluated to true.

     1	     expression evaluated to false or expression was missing.

     >1      An error occurred.

EXAMPLES

     Implement test FILE1 -nt FILE2 using only POSIX functionality:

	   test -n "$(find -L -- FILE1 -prune -newer FILE2 2>/dev/null)"

     This can be modified using non-standard find(1) primaries like -newerca to compare other timestamps.

COMPATIBILITY

     For compatibility with some other implementations, the = primary can be substituted with == with the same meaning.

SEE ALSO

     builtin(1), expr(1), find(1), sh(1), stat(1), symlink(7)

STANDARDS

     The test utility implements a superset of the IEEE Std 1003.2 (``POSIX.2'') specification.  The primaries <, ==, >, -ef, -nt, -ot, -G, and -O
     are extensions.

BUGS

     Both sides are always evaluated in -a and -o.  For instance, the writable status of file will be tested by the following command even though
     the former expression indicated false, which results in a gratuitous access to the file system:
	   [ -z abc -a -w file ]
     To avoid this, write
	   [ -z abc ] && [ -w file ]

BSD
								   June 1, 2013 							       BSD