
  VMS (OpenVMS):

  Building:

     On VMS, two build methods are provided: a command procedure, and
     description files for MMS or MMK.  Both methods must be run from
     the main directory, not the [.VMS] subdirectory.

     A simple build using the command procedure looks like this:
          @ [.VMS]BUILD_ZIP.COM

     A simple build using MMS or MMK looks like this:
          MMS /DESCRIP = [.VMS]DESCRIP.MMS      ! Or, with MMK, ...
          MMK /DESCRIP = [.VMS]DESCRIP.MMS

     Various options for each build method are explained in comments in
     the main builder file, either BUILD_ZIP.COM or DESCRIP.MMS.

      Note that on non-VAX systems with VMS V7.2 or later (and with a
      sufficiently new C compiler), Zip 3.0 can support files (both data
      files and Zip archives) larger than 2GB.  For the greatest
      compatibility with previous Zip versions, the builders by default
      create old-style small-file programs.  The user must specify the
      appropriate builder command-line option to create
      large-file-capable programs.

     Here are some more complex build examples:

     o Build with the large-file option enabled (non-VAX only):

          @ [.VMS]BUILD_ZIP LARGE
       or:
          MMS /DESC = [.VMS] /MACRO = LARGE=1

     o Re-link the executables (small-file and large-file):

          @ [.VMS]BUILD_ZIP LINK
          @ [.VMS]BUILD_ZIP LARGE LINK
       or
          MMK /DESC = [.VMS] CLEAN_EXE  ! Deletes existing executables.
          MMK /DESC = [.VMS]            ! Builds new executables.
          MMK /DESC = [.VMS] /MACRO = LARGE=1 CLEAN_EXE
          MMK /DESC = [.VMS] /MACRO = LARGE=1

     o Build a large-file product from scratch, for debug, getting
       compiler listings and link maps:

          MMS /DESC = [.VMS] CLEAN
          MMS /DESC = [.VMS] /MACRO = (DBG=1, LARGE=1. LIST=1)

     On VAX, the builders attempt to cope with the various available C
     compilers, DEC/Compaq/HP C, VAX C, or GNU C.  If DEC/Compaq/HP C is
     not available or not desired, comments in the relevant builder file
     explain the command-line options used to select a different
     compiler.

     By default, Zip uses the "deflate" compression method.  To add
     support for the optional "bzip2" compression method, first obtain
     and build the bzip2 software (http://www.bzip.org/ or, for a more
     VMS-friendly kit, http://antinode.info/dec/sw/bzip2.html).  Then,
     define the macro IZ_BZIP2 on the BUILD_ZIP.COM or MMS/MMK command
     line to specify the directory where the bzip2 files may be found.
     For example:

          @ [.VMS]BUILD_ZIP LARGE -
           IZ_BZIP2=SYS$SYSDEVICE:[UTILITY.SOURCE.BZIP2.BZIP2-1_0_3C_VMS]
       or:
          MMS /DESC = [.VMS] /MACRO = (LARGE=1, -
           IZ_BZIP2=SYS$SYSDEVICE:[UTILITY.SOURCE.BZIP2.BZIP2-1_0_3C_VMS])

     Note that historically, Zip has been built with the default
     compiler option, /NAMES = UPPERCASE, while bzip2 is normally built
     with /NAMES = AS_IS, to avoid name collisions.  With modern
     compilers, the "#pragma names" directives in [.VMS]BZLIB.H will
     handle these differences without user intervention.  An old
     compiler (for example, DEC C V4.0-000) will emit complaints
     %CC-I-UNKNOWNPRAGMA, and will mishandle the bzip2 library function
     names, which will cause the link to fail.  To solve this problem,
     either build the bzip2 BZ_NO_STDIO object library with /NAMES =
     UPPERCASE, or else build Zip with /NAMES = AS_IS.  For example:

          @ [.VMS]BUILD_ZIP LARGE "CCOPTS=/NAMES=AS_IS" -
           IZ_BZIP2=SYS$SYSDEVICE:[UTILITY.SOURCE.BZIP2.BZIP2-1_0_3C_VMS]
       or:
          MMS /DESC = [.VMS] /MACRO = (LARGE=1, "CCOPTS=/NAMES=AS_IS", -
           IZ_BZIP2=SYS$SYSDEVICE:[UTILITY.SOURCE.BZIP2.BZIP2-1_0_3C_VMS])

     System-architecture-specific files (like objects and executables)
     are placed in separate directories, such as [.ALPHA], [.IA64], or
     [.VAX].  Large-file products get their own directories, [.ALPHAL]
     or [.IA64L].  On VAX, VAX C products are placed in [.VAXV], GNU C
     products in [.VAXG].  Each product builder announces what the
     destination directory will be when it is run.

     Common files, such as the help libraries (ZIP.HLP for the default
     UNIX-like command-line interface, ZIP_CLI.HLP for the VMS-like
     command-line interface), are placed in the main directory.  With a
     mixed-architecture VMS cluster, the same main directory on a shared
     disk may be used by all system types.  (Using the NOHELP option
     with BUILD_ZIP.COM can keep it from making the same help files
     repeatedly.)  Building the help files is detailed below.

  Completing installation:

     To complete the installation, the executables may be left in place,
     or moved (or copied) to a convenient place.  While other methods
     (like DCL$PATH) exist, most users define symbols to make the Zip
     executables available as foreign commands.  These symbol definitions
     may be placed in a user's SYS$LOGIN:LOGIN.COM, or in a more central
     location, like SYS$MANAGER:SYLOGIN.COM.  Typical symbol definitions
     might look like these:

           ZIP :== $ dev:[dir]ZIP.EXE            ! UNIX-like command line.
   or:
           ZIP :== $ dev:[dir]ZIP_CLI.EXE        ! VMS-like command line.

     On a non-VAX system, different symbols could be defined for the
     small-file and large-file programs.  For example:

           ZIPS  :== $ dev:[dir.ALPHA]ZIP.EXE    ! ZIPS = small-file Zip.
           ZIP*L :== $ dev:[dir.ALPHAL]ZIP.EXE   ! ZIP[L] = large-file Zip.

     The builders create help text files, ZIP.HLP and ZIP_CLI.HLP.
     These may be incorporated into an existing help library, or a separate
     Zip help library may be created using commands like these, using
     either ZIP.HLP (as shown) or ZIP_CLI.HLP:

           $ LIBRARY /HELP dev:[dir]existing_library.HLB ZIP.HLP

           $ LIBRARY /CREATE /HELP ZIP.HLB ZIP.HLP

     Zip help may then be accessed from a separate Zip help library
     using a command like:

           $ HELP /LIBRARY = device:[directory]ZIP.HLB

     For greater ease, the user (or system manager) may define a
     HLP$LIBRARY logical name to allow the HELP utility to find the Zip
     help library automatically.  See HELP HELP /USERLIBRARY for more
     details.   The command procedure HLP_LIB_NEXT.COM may be used to
     determine the next available HLP$LIBRARY logical name, and could be
     adapted to define a HLP$LIBRARY logical name for a Zip help library.

     The builders also create VMS message files, ZIP_MSG.EXE, in the
     destination directory with the program executables.  A user may
     gain DCL access to the Zip error messages using a command like:

           $ SET MESSAGE device:[directory]ZIP_MSG.EXE

     For system-wide access, the system manager may move or copy this
     file to SYS$MESSAGE, although this could cause some confusion if
     multiple versions of Zip are used on the system, and their error
     message source files differ.

     Some further information may be found in the files
     [.VMS]00README.TXT and [.VMS]00BINARY.VMS, though much of what's
     there is now obsolete.
