test(1)test(1)NAME
test, [ - Evaluates conditional expressions
SYNOPSIStest [expression]
[[expression]]
STANDARDS
Interfaces documented on this reference page conform to industry stan‐
dards as follows:
test: XCU5.0
[: XCU5.0
Refer to the standards(5) reference page for more information about
industry standards and associated tags.
OPTIONS
None
OPERANDS
The expression to be evaluated as true or false. This expression is
constructed from the operators and elements explained in the DESCRIP‐
TION section.
DESCRIPTION
The test command evaluates an expression constructed of functions and
operators. If the value of expression is true, test returns an exit
value of zero (0); otherwise, it returns FALSE, a nonzero exit value.
The test command also returns a nonzero exit value if there are no
arguments.
The alternate form of the command surrounds expression with brackets ([
]). When you use this form, you must surround the brackets with spa‐
ces.
The test Expressions
All of the listed functions and operators are separate arguments to
test.
The following functions are used to construct expression: TRUE if file
exists and has read permission. TRUE if file exists and has write per‐
mission. TRUE if file exists and has execute permission. TRUE if file
exists and is a regular file. TRUE if file exists and is a directory.
TRUE if file exists. TRUE if file exists and is a character-special
file. TRUE if file exists and is a block-special file. TRUE if file
exists and is a named pipe (FIFO). [Tru64 UNIX] TRUE if file exists
and is a soft link. Synonym for -L expression. TRUE if file exists
and is a soft link. Synonym for -h expression. TRUE if file exists
and its set-user ID bit is set. TRUE if file exists and its set-group
ID bit is set. [Tru64 UNIX] TRUE if file exists and its sticky bit is
set. TRUE if file exists and has a size greater than zero (0). TRUE
if the open file with file descriptor number file_descriptor (1 by
default) is associated with a terminal device. TRUE if the length of
string1 is zero (0). TRUE if the length of string1 is nonzero. TRUE
if string1 and string2 are identical. TRUE if string1 and string2 are
not identical. TRUE if string1 is not the null string. TRUE if the
integers number1 and number2 are algebraically equal. Any of the com‐
parisons -ne, -gt, -ge, -lt, and -le can be used in place of -eq.
The listed functions can be combined with the following operators:
Unary negation operator. Binary AND operator. Binary OR operator (the
-a operator has higher precedence than the -o operator). [Tru64
UNIX] Parentheses for grouping.
EXIT STATUS
The following exit values are returned: The test command evaluated
expression and its value is TRUE. The test command evaluated expres‐
sion and is value is FALSE, or there are no arguments. An error
occurred.
EXAMPLES
To test whether a file exists and is not empty, enter: if test ! -s
"$1" then echo $1 does not exist or is empty. fi
If the file specified by the first positional parameter to the
shell procedure does not exist, this displays an error message.
If $1 exists, it displays nothing. There must be a space
between -s expression and the file name.
The double quotes around $1 ensure that the test will work prop‐
erly even if the value of $1 is the empty string. If the double
quotes are omitted and $1 is the empty string, test displays the
error message test: parameter expected. To do a complex compar‐
ison, enter: if [ $# -lt 2 -o ! -s "$1" ] then exit fi
If the shell procedure was given fewer than two positional
parameters or the file specified by $1 does not exist, then this
exits the shell procedure. The special shell variable $# repre‐
sents the number of positional parameters entered on the command
line that started this shell procedure.
ENVIRONMENT VARIABLES
The following environment variables affect the execution of test: Pro‐
vides a default value for the internationalization variables that are
unset or null. If LANG is unset or null, the corresponding value from
the default locale is used. If any of the internationalization vari‐
ables contain an invalid setting, the utility behaves as if none of the
variables had been defined. If set to a non-empty string value, over‐
rides the values of all the other internationalization variables.
Determines the locale for the interpretation of sequences of bytes of
text data as characters (for example, single-byte as opposed to multi‐
byte characters in arguments). Determines the locale for the format
and contents of diagnostic messages written to standard error. Deter‐
mines the location of message catalogues for the processing of LC_MES‐
SAGES.
SEE ALSO
Commands: csh(1), find(1), ksh(1), Bourne shell sh(1b), POSIX shell
sh(1p)
Standards: standards(5)test(1)
