test - condition evaluation utility
test expression
[ expression ]
The test utility evaluates the expression and, if it evaluates to true,
returns a zero (true) exit status; otherwise it returns 1
(false). If no
expression is 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 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 (default 1) 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 for compatibility purposes. 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.
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.
s1 True if s1 is not the null string.
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.
Symbolic links are followed for all primaries except -h and
-L.
The test grammar is inherently ambiguous. In order to assure a degree of
consistency, the cases described in IEEE Std 1003.2
(``POSIX.2'') section
D11.2/4.62.4 are evaluated consistently according to the
rules specified
in the standards document. All other cases are subject to
the ambiguity
in the command semantics.
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.
The test utility implements a superset of the IEEE Std
1003.2
(``POSIX.2'') specification.
OpenBSD 3.6 May 31, 1993
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