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TEST(1) 	       DragonFly 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 program. 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 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. -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 inte- ger 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 eval- uate 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 iden- tical 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 sub- ject to the ambiguity in the command semantics. In particular, only expressions containing -a, -o, ( or ) can be ambigu- ous.

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 ] DragonFly 4.1 June 1, 2013 DragonFly 4.1