Manual: test(1)

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test(1)								      test(1)



NAME
  test,	[  - Evaluates conditional expressions

SYNOPSIS

  test expression

  [ expression ]

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 0 (zero); otherwise, it returns a nonzero (false) 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 spaces.

  The test Expressions

  All of the listed functions and operators are	separate arguments to test.

  The following	functions are used to construct	expression:

  -r file
      TRUE if file exists and has read permission.

  -w file
      TRUE if file exists and has write	permission.

  -x file
      TRUE if file exists and has execute permission.

  -f file
      TRUE if file exists and is a regular file.

  -d file
      TRUE if file exists and is a directory.

  -e file
      TRUE if file exists.

  -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).

  -h file
      TRUE if file exists and is a soft	link.  Synonym for -L.

  -L file
      TRUE if file exists and is a soft	link.  Synonym for -h.

  -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 0	(zero).

  -t [file_descriptor]
      TRUE if the open file with file descriptor number	file_descriptor	(1 by
      default) is associated with a terminal device.

  -z string1
      TRUE if the length of string1 is 0 (zero).

  -n string1
      TRUE if the length of string1 is nonzero.

  string1 = string2
      TRUE if string1 and string2 are identical.

  string1 and string2 are not identical.

  string1 is not the null string.

  number1 -eq number2
      TRUE if the integers number1 and number2 are algebraically equal.	 Any
      of the comparisons -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.

  -a  Binary AND operator.

  -o  Binary OR	operator (-a has higher	precedence than	-o).

  \( expression	\)
      Parentheses for grouping.

EXAMPLES

   1.  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.  Note that there must be a space between
       -s and the filename.

       The double quotes around	$1 ensure that the test	will work properly
       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.

   2.  To do a complex comparison, 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 $# represents the	number of
       positional parameters entered on	the command line that started this
       shell procedure.

EXIT VALUES

  The test command evaluates expression	and, if	its value is TRUE, returns an
  exit value of	0; otherwise, it returns a nonzero (FALSE) exit	value; the
  test command also returns a nonzero exit value if there are no arguments.

RELATED	INFORMATION

  Commands:  csh(1), find(1), ksh(1), sh(1).