VMS Help  —  CHECKSUM  Qualifiers

1    /ALGORITHM

       /ALGORITHM=option
       /ALGORITHM=XOR (default)

    Selects the algorithm used for file checksums. The default is the
    XOR algorithm for data within records. Options include:

    o  CRC - A CRC-32 algorithm for all bytes within the file
       (possible record structures are ignored); this algorithm is
       also known as AUTODIN II, Ethernet, or FDDI CRC.

    o  MD5 - The MD5 digest, as published by Ronald L. Rivest
       (RFC 1321), for all bytes within the file (possible record
       structures are ignored).

    o  SHA1 - A Secure Hash Algorithm for all bytes within the file
       (possible record structures are ignored). A 160-bit (20-byte)
       hash function designed by the National Security Agency (NSA).

    o  SHA256 - A Secure Hash Algorithm for all bytes within the file
       (possible record structures are ignored). A 256-bit (32-byte)
       hash function designed by the National Security Agency (NSA).

    o  XOR - An XOR algorithm for all data, according to the record
       structure of the file.

2    /ALPHA

    Calculates an Alpha-type checksum and is only useful with the
    /IMAGE qualifier on Integrity server systems (that is, it
    checksums Alpha images on Integrity server systems). It is set
    by default on Alpha platforms.

3    /FILE

       /FILE (default)

    Calculates a file checksum.

    By default, the XOR algorithm (/ALGORITHM=XOR) is used for the
    checksum. The /FILE qualifier also implies a default file type
    of .DAT. By default, unsigned decimal checksum value is saved in
    the DCL symbol CHECKSUM$CHECKSUM and not output to the screen. By
    specifying /SHOW=DATA, the full filename of the specified input
    file is output in addition to the file checksum, an unsigned
    decimal value.

    The /ALPHA, /I64, or /VAX platform qualifiers do not influence
    the file checksum result. However, /ALPHA and /VAX prohibit the
    /SHOW qualifier because these qualifiers were not available on
    the original Checksum utility for Alpha systems.

4    /I64

    Calculates an I64-type checksum and is only useful on Alpha
    systems with /IMAGE or /OBJECT (that is, it checksums Integrity
    servers images or objects on Alpha systems). The /I64 qualifier
    is set by default on Integrity servers platforms.

5    /IMAGE

    Calculates a checksum of all image bytes. The image structure
    is followed to include only the image bytes into the checksum.
    Invariant data, such as the linker version and the link date, are
    omitted.

    For Integrity servers images (that is, Integrity servers
    formatted files), a CRC checksum is calculated and additional
    information is output to SYS$OUTPUT, including the following:

    o  The resulting full filename and checksums for the image
       segments

    o  The header checksums and the overall image checksum

    The output values are shown in hexadecimal notation. The DCL
    symbol, CHECKSUM$CHECKSUM, shows the result in hexadecimal
    notation.

    For Alpha and VAX images, an XOR checksum is calculated and
    additional information is output to SYS$OUTPUT:

    o  The resulting full filename and checksums for the image
       sections

    o  The header checksum and the overall image checksum

    The output checksum values are in hexadecimal notation. However,
    the result in the DCL symbol CHECKSUM$CHECKSUM is in unsigned
    decimal notation.

                                   NOTE

       For Alpha and VAX images, the unsigned decimal notation
       of the checksum value in the DCL symbol CHECKSUM$CHECKSUM
       retains compatibility with the previous checksum tool.

    The /IMAGE qualifier implies the default file type of .EXE. For
    Integrity servers images, this qualifier also implies the default
    keyword values HEADERS and SEGMENTS for the /SHOW qualifier.

6    /OBJECT

    Calculates a CRC checksum of all Integrity servers object bytes.

    The /OBJECT qualifier follows the ELF-64 object structure to
    include only the object bytes into the checksum. Invariant data,
    as the language processor version and the generation date, are
    omitted.

    Additional information is output to SYS$OUTPUT, including the
    following:

    o  The resulting full filename of the specified input file

    o  The checksums for the object sections, headers, and the
       overall object checksum

    The output checksum values are in hexadecimal notation. The
    result provided in the DCL symbol, CHECKSUM$CHECKSUM, is in
    hexadecimal notation.

    The /OBJECT qualifier implies the default file type of .OBJ. This
    qualifier also implies the default keyword values HEADERS and
    SECTIONS for the /SHOW qualifier.

    On Alpha platforms, it is only applicable with the /Integrity
    servers qualifier.

7    /OUTPUT

       /OUTPUT[=filespec]
       /NOOUTPUT

    The /OUTPUT qualifier controls where the output of the command is
    sent. The /NOOUTPUT qualifier suppresses output.

    If you specify /OUTPUT and a file specification
    (/OUTPUT=filespec), the output is sent to the specified file,
    rather than to the current output device, SYS$OUTPUT. If you do
    not enter the qualifier, or if you enter the /OUTPUT qualifier
    without a file specification, the output is sent to SYS$OUTPUT.

    Using the /OUTPUT qualifier does not affect the result (that is,
    the DCL symbol CHECKSUM$CHECKSUM).

8    /SHOW

       /SHOW=(option[,...])

    Controls which checksum and additional information is output to
    the device.

    Options for this qualifier are as follows:

    o  ALL - Sets all of the applicable options, with the following
       restrictions:

       -  For file checksums, only the DATA keyword is allowed.

       -  For image checksums, all keywords are allowed.

       -  For object checksums, the SEGMENT keyword is not allowed.

    o  DATA - Outputs the full file name and the file checksum. For
       compatibility, this option is available for /FILE.

    o  EXCLUDED - Formats the data excluded from the image or object
       checksums.

    o  HEADERS - Output checksums of all Integrity servers headers.
       This option is set by default for /IMAGE and /OBJECT.

    o  SECTIONS - Output checksums of all ELF-64 sections. This
       option is set by default for /OBJECT.

    o  SEGMENTS - Output checksums of all ELF-64 program segments.
       This option is set by default for /IMAGE.

9    /VAX

    Calculates a VAX-type checksum and is only useful on Integrity
    servers or Alpha systems with /IMAGE to checksum VAX images on
    non-VAX systems.
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