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test(1)
NAME
  test, [ - Evaluates conditional expressions

SYNOPSIS
  test [expression]

  [[expression]]

STANDARDS
  Interfaces documented on this reference page conform to industry standards
  as follows:

  test:	 XPG4, XPG4-UNIX

  [:  XPG4, XPG4-UNIX

  Refer to the standards(5) reference page for more information about
  industry standards and associated tags.

OPTIONS
  None

OPERANDS
  expression
      The expression to be evaluated as true or false.	This expression is
      constructed from the operators and elements explained in the
      DESCRIPTION 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 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
      [DIGITAL]	 TRUE if file exists and is a soft link.  Synonym for -L
      expression.

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

  -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
      [DIGITAL]	 TRUE if file exists and its sticky bit is set.

  -s file
      TRUE if file exists and has a size greater than zero (0).

  -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 zero (0).

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

  string1 = string2
      TRUE if string1 and string2 are identical.

  string1 != string2
      TRUE if string1 and string2 are not identical.

  string1
      TRUE if 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 (the -a operator has higher precedence than the -o
      operator).

  \( expression \)
      [DIGITAL]	 Parentheses for grouping.

EXIT STATUS
  The following exit values are returned:

  0   The test command evaluated expression and its value is TRUE.

  1   The test command evaluated expression and is value is FALSE, or there
      are no arguments.

  >1  An error occurred.

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.  There must be a space between -s
       expression and the file name.

       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.

ENVIRONMENT VARIABLES
  The following environment variables affect the execution of test:

  LANG
      Provides 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
      variables contain an invalid setting, the utility behaves as if none of
      the variables had been defined.

  LC_ALL
      If set to a non-empty string value, overrides the values of all the
      other internationalization variables.

  LC_CTYPE
      Determines the locale for the interpretation of sequences of bytes of
      text data as characters (for example, single-byte as opposed to
      multibyte characters in arguments).

  LC_MESSAGES
      Determines the locale for the format and contents of diagnostic
      messages written to standard error.

  NLSPATH
      Determines the location of message catalogues for the processing of
      LC_MESSAGES.

SEE ALSO
  Commands:  csh(1), find(1), ksh(1), Bourne shell sh(1b), POSIX shell sh(1p)

  Standards:  standards(5)