Procedure

     WDINDX ( Index of a Word Within a String )

     INTEGER FUNCTION WDINDX ( STRING, WORD )

Abstract

     Find the index of a word within a string. If the word does not
     exist as a word within the string, the value zero is returned.

Required_Reading

     None.

Keywords

     PARSING
     SEARCH
     WORD

Declarations

     IMPLICIT NONE

     CHARACTER*(*)    STRING
     CHARACTER*(*)    WORD

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     STRING     I   String of characters, potentially containing words
     WORD       I   A string of consecutive printable letters.

     The function returns the location of WORD within STRING.

Detailed_Input

     STRING   is a string of characters, potentially containing the
              word.

              Leading and trailing blanks are not significant in
              STRING.

     WORD     is a string of consecutive printable characters.

              Leading and trailing blanks are not significant in
              WORD.

Detailed_Output

     The function returns the location of WORD within STRING, providing
     the index of the first letter of WORD within the input STRING. If
     WORD does not exist or WORD is blank, the function returns zero.

Parameters

     None.

Exceptions

     Error free.

Files

     None.

Particulars

     A word within a string is a substring beginning and ending with a
     non-blank characters that is delimited by blanks on each end. (A
     blank is assumed to precede and follow the first and last
     characters of a string.)

     Given a word, this routine returns the index of the first letter
     of the first word of STRING that matches the word.

Examples

     STRING:
                      1         2         3         4
     WORD    1234567890123456789012345678901234567890123456    WDINDX
     ------  ----------------------------------------------    ------
     'POT'   'PUT THE POTATOES IN THE POT'                     25
     'TOES'                                                    0
     'PUT'                                                     1
     'THE'                                                     5
     'IN THE'                                                  18
     'THE PO'                                                  0

Restrictions

     None.

Literature_References

     None.

Author_and_Institution

     J. Diaz del Rio    (ODC Space)
     W.L. Taber         (JPL)

Version

    SPICELIB Version 1.1.0, 03-OCT-2021 (JDR)

        Added IMPLICIT NONE statement.

        Edited the header to comply with NAIF standard.

    SPICELIB Version 1.0.1, 10-MAR-1992 (WLT)

        Comment section for permuted index source lines was added
        following the header.

    SPICELIB Version 1.0.0, 31-JAN-1990 (WLT)