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

    The Locate a Character routine locates a character in a string
    by comparing successive bytes in the string with the character
    specified. The search continues until the character is found or
    the string has no more characters. LIB$LOCC makes the VAX LOCC
    instruction available as a callable routine.

    Format

      LIB$LOCC  character-string ,source-string

1 - Returns

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

    The relative position from the start of source-string to the
    first equal character or zero if no match is found.

2 - Arguments

 character-string

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

    String whose initial character is used by LIB$LOCC in the
    search. The character-string argument contains the address of
    a descriptor pointing to this string. Only the first character of
    character-string is used, and its length is not checked.

 source-string

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

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