Examples

   1.$ FILE_SPEC = "MYFILE.DAT;1"
     $ NAME_LENGTH = F$LOCATE(".",FILE_SPEC)

     The F$LOCATE function in this example returns the position of
     the period (.)  in the string with respect to the beginning of
     the string. The period is in offset position 6, so the value
     6 is assigned to the symbol NAME_LENGTH. Note that NAME_LENGTH
     also equals the length of the file name portion of the file
     specification MYFILE.DAT, that is, 6.

     The substring argument, the period, is specified as a string
     literal and is therefore enclosed in quotation marks (" ").
     The string argument FILE_SPEC is a symbol, so it should not be
     placed within quotation marks. It is automatically replaced by
     its current value during the processing of the function.

   2.$ INQUIRE TIME "Enter time"
     $ IF F$LOCATE(":",TIME) .EQ. F$LENGTH(TIME) THEN -
       GOTO NO_COLON

     This section of a command procedure compares the results of the
     F$LOCATE and F$LENGTH functions to see if they are equal. This
     technique is commonly used to determine whether a character or
     substring is contained in a string.

     In the example, the INQUIRE command prompts for a time value
     and assigns the user-supplied time to the symbol TIME. The IF
     command checks for the presence of a colon (:)  in the string
     entered in response to the prompt. If the value returned by
     the F$LOCATE function equals the value returned by the F$LENGTH
     function, the colon is not present. You use the .EQ. operator
     (rather than .EQS.) because the F$LOCATE and F$LENGTH functions
     return integer values.

     Note that quotation marks are used around the substring
     argument, the colon, because it is a string literal; however,
     the symbol TIME does not require quotation marks because it is
     automatically evaluated as a string expression.