VMS Help RTL Routines, LIB$, LIB$INDEX  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    The Index to Relative Position of Substring routine returns an
    index, which is the relative position of the first occurrence of
    a substring in the source string.

    Format

      LIB$INDEX  source-string ,sub-string

1 - Returns

    OpenVMS usage:longword_unsigned
    type:         longword (unsigned)
    access:       write only
    mechanism:    by value

    The relative position of the first character of the substring if
    found, or zero if not found.

    On Alpha systems, if the relative position of the substring can
    exceed 2**32-1, assign the return value to a quadword to ensure
    that you retrieve the correct relative position.

2 - Arguments

 source-string

    OpenVMS usage:char_string
    type:         character string
    access:       read only
    mechanism:    by descriptor

    Source string to be searched by LIB$INDEX. The source-string
    argument is the address of a descriptor pointing to this source
    string.

 sub-string

    OpenVMS usage:char_string
    type:         character string
    access:       read only
    mechanism:    by descriptor

    Substring to be found. The sub-string argument is the address of
    a descriptor pointing to this substring.