test(1) test(1)
NAME
test - condition evaluation command
SYNOPSIS
test expr
[] [expr] []
DESCRIPTION
test evaluates the expression expr and, if its value is
true, returns a zero (true) exit status; otherwise, a non-
zero (false) exit status is returned; test also returns a
non-zero exit status if there are no arguments. The super-
user is always granted execute permission even though 1.
execute permission is meaningful only for directories and
regular files, and 2. exec requires that at least one
execute mode bit be set for a regular file to be executable.
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.
-d file true if file exists and is a directory.
-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.
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-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.
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 that all the operators and flags are separate
arguments to test. Notice also that parentheses are
meaningful to the shell and, therefore, must be escaped.
EXAMPLE
test is typically used in shell scripts (sh(1)), as in the
following example, which prints the message foo is a
directory if it is found to be one when test is run.
if test -d foo
then
echo "foo is a dir"
fi
SEE ALSO
find(1), sh(1),
``SH: The Bourne shell'' in Oreo User Interface.
WARNING
In the second form of the command (i.e., the one that uses
[] [expr] [], rather than the word test), the square
brackets must be delimited by blanks.
Some UNIX® systems do not recognize the second form of the
command.
Note that test is built into /bin/ksh and /bin/sh and will
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not work in /bin/csh.
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