The Calculate a Cyclic Redundancy Check routine calculates the
    cyclic redundancy check (CRC) for a data stream.

    Format

      LIB$CRC  crc-table ,initial-crc ,stream

1  –  Returns

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

    The computed cyclic redundancy check.

2  –  Arguments

 crc-table

    OpenVMS usage:vector_longword_signed
    type:         longword integer (signed)
    access:       read only
    mechanism:    by reference, array reference

    The 16-longword cyclic redundancy check table created by a call
    to LIB$CRC_TABLE. The crc-table argument is the address of a
    signed longword integer containing this table. Because this table
    is created by LIB$CRC_TABLE and then used as input in LIB$CRC,
    your program must call LIB$CRC_TABLE before it calls LIB$CRC.

 initial-crc

    OpenVMS usage:longword_signed
    type:         longword integer (signed)
    access:       read only
    mechanism:    by reference

    Initial cyclic redundancy check. The initial-crc argument is
    the address of a signed longword integer containing the initial
    cyclic redundancy check.

 stream

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

    Data stream for which LIB$CRC is calculating the CRC. The stream
    argument is the address of a descriptor pointing to the data
    stream.