test(1)

test -- condition evaluation command

Synopsis

test expr
[ expr ]

Description

test evaluates the expression expr and, if its value is true, sets a zero (true) exit status; otherwise, a non-zero (false) exit status is set; test also sets a non-zero exit status if there are no arguments. When permissions are tested, the effective user ID of the process is used. test processes supplementary code set characters in expr according to the locale specified in the LC_CTYPE environment variable [see LANG on environ(5)].

All operators, flags, and brackets (brackets used as shown in the second Synopsis line) must be separate arguments to the test command; normally these items are separated by spaces.

The following primitives are used to construct expr. Most of these primitives perform unary operations: that is, they take only one argument. If more than one argument follows any of the r, w, x, f, d, h, c, b, p, u, g, k, s, t, z, or n operators, only the first argument is examined; the others are ignored (unless a -a or a -o is the second argument).

-r file: true if file exists and is readable.
-w file: true if file exists and is writable.
-x file: true if file exists and is executable.
-f file: true if file exists and is a regular file. Alternatively, if /usr/bin/sh users specify /usr/ucb before /usr/bin in their PATH environment variable, then test will return true if file exists and is not a directory. This is also the default for /usr/bin/csh users.
-d file: true if file exists and is a directory.
-h file: true if file exists and is a symbolic link. With all other primitives (except -L file), the symbolic links are followed by default.
-c file: true if file exists and is a character special file.
-b file: true if file exists and is a block special file.
-p file: true if file exists and is a named pipe (fifo).
-u file: true if file exists and its set-user-ID bit is set.
-g file: true if file exists and its set-group-ID bit is set.
-k file: true if file exists and its sticky bit is set.
-s file: true if file exists and has a size greater than zero.
-t [fildes]: true if the open file whose file descriptor number is fildes (1 by default) is associated with a terminal device.
-z s1: true if the length of string s1 is zero.
-n s1: true if the length of the string s1 is non-zero.
s1 = s2: true if strings s1 and s2 are identical.
s1 != s2: true if strings s1 and s2 are not identical.
s1: true if s1 is not the null string.
n1 -eq n2: true if the integers n1 and n2 are algebraically equal. Any of the comparisons -ne, -gt, -ge, -lt, and -le may be used in place of -eq.
-L file: true if file exists and is a symbolic link. With all other primitives (except -h file), the symbolic links are followed by default.

These primaries may be combined with the following operators:

``!'': unary negation operator.
-a: binary and operator.
-o: binary or operator (-a has higher precedence than -o).
(expr): parentheses for grouping. Notice also that parentheses are meaningful to the shell and, therefore, must be quoted.

Files

/usr/lib/locale/locale/LC_MESSAGES/uxcore.abi: language-specific message file [See LANG on environ(5).]

References

find(1), csh(1), sh(1), ksh88(1), ksh(1)

Notices

The not-a-directory alternative to the -f option is a transition aid for applications and may not be supported in future releases.

The -L option is a migration aid for users of other shells which have similar options and may not be supported in future releases.

If you test a file you own (the -r, -w, or -x tests), but the permission tested does not have the owner bit set, a non-zero (false) exit status will be returned even though the file may have the group or other bit set for that permission. The correct exit status will be set if you are a privileged user.

The = and != operators have a higher precedence than the -r through -n operators, and = and != always expect arguments; therefore, = and != cannot be used with the -r through -n operators.