The
test utility evaluates
expression and, if it evaluates to true, returns a zero (true) exit status; otherwise it returns 1 (false). If
expression is not given,
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.
-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 exists and 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 indicates 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. This operator is retained for compatibility with previous versions of this program. Do not rely on its existence; use -h instead.
-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 ASCII value of their characters.
s1 > s2
True if string s1 comes after s2 based on the ASCII 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.
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.
Note that all file tests with the exception of
-h and
-L follow symbolic links and thus evaluate the test for the file pointed at.