The Analyze String Descriptor routine extracts the length and
    starting address of the data for a variety of string descriptor
    classes.

    Format

      STR$ANALYZE_SDESC  input-descriptor ,integer-length

                         ,data-address

1  –  Corresponding JSB Entry Point

      STR$ANALYZE_SDESC_R1

2  –  Returns

    OpenVMS usage:word_unsigned
    type:         word (unsigned)
    access:       write only
    mechanism:    by value

    Length of the data. The return value is the same value returned
    to the integer-length argument.

3  –  Arguments

 input-descriptor

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

    Input descriptor from which STR$ANALYZE_SDESC extracts the length
    of the data and the address at which the data starts. The input-
    descriptor argument is the address of a descriptor pointing to
    the input data.

 integer-length

    OpenVMS usage:word_unsigned
    type:         word (unsigned)
    access:       write only
    mechanism:    by reference for CALL entry point, by value for JSB
                  entry point

    Length of the data; this length is extracted from the descriptor
    by STR$ANALYZE_SDESC. The integer-length argument is the address
    of an unsigned word integer into which STR$ANALYZE_SDESC writes
    the data length.

 data-address

    OpenVMS usage:address
    type:         longword (unsigned)
    access:       write only
    mechanism:    by reference for CALL entry point, by value for JSB
                  entry point

    Address of the data; this address is extracted from the
    descriptor by STR$ANALYZE_SDESC. The data-address argument is an
    unsigned longword into which STR$ANALYZE_SDESC writes the address
    of the data.