test(1) (Essential Utilities) test(1)
NAME
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.
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:
-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/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.
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test(1) (Essential Utilities) test(1)
-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.
SEE ALSO
find(1), sh(1).
NOTES
The not-a-directory alternative to the -f option is a transition aid
for BSD 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
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test(1) (Essential Utilities) test(1)
be set if you are super-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.
If more than one argument follows the -r through -n operators, only
the first argument is examined; the others are ignored, unless a -a
or a -o is the second argument.
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