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TEST(1) |
General Commands Manual |
TEST(1) |
NAME
test, [ — condition evaluation utility
DESCRIPTION
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.
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-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.
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-t file_descriptor
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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
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True if the length of string is zero.
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-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.
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-O file
-
True if file exists and its owner matches the effective user id of this process.
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-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.
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file1 -ot file2
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True if file1 exists and is older than file2.
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file1 -ef file2
-
True if file1 and file2 exist and refer to the same file.
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string
-
True if string is not the null string.
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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.
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s1 > s2
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True if string s1 comes after s2 based on the ASCII value of their characters.
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n1 -eq n2
-
True if the integers n1 and n2 are algebraically equal.
-
n1 -ne n2
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True if the integers n1 and n2 are not algebraically equal.
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n1 -gt n2
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True if the integer n1 is algebraically greater than the integer n2.
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n1 -ge n2
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True if the integer n1 is algebraically greater than or equal to the integer n2.
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n1 -lt n2
-
True if the integer n1 is algebraically less than the integer n2.
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n1 -le n2
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True if the integer n1 is algebraically less than or equal to the integer n2.
These primaries can be combined with the following operators:
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! expression
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True if expression is false.
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expression1 -a expression2
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True if both expression1 and expression2 are true.
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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.
GRAMMAR AMBIGUITY
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 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.
EXIT STATUS
The
test utility exits with one of the following values:
-
0
-
expression evaluated to true.
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1
-
expression evaluated to false or was missing.
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>1
-
An error occurred.
STANDARDS
The test utility implements a superset of the IEEE Std 1003.2 (“POSIX.2”) specification.