zipunzip.pas

script language

         One good side-effect of using the central directory is speed. We
      can now read a zip file's contents very quickly.

      This release also lets you read the main zip file comments, and the
      comments for individual file entries.  However, these comments can
      only be read - you can not create zip comments with v1.50.

      These new read-only runtime properties tell you about the zip file.
      These are valid after a zip file's contents have been read (which
      happens when you assign something to ZipFilename).
        ZipFileSize: size of entire Zip file (if spanning, then size of
                     the last chunk)
        SFXOffset: size of the Self-extracting code at the beginning (only
                   used for non-spanning archives)
        ZipSOC:  Start-Of-Central-Dir location
        ZipEOC:  End-Of-Central-Dir location
        ZipComment: The text comment for this zip file. Up to 64K in size.

      If individual files have comments, you can read them from the ZipDirEntry
      record when you examine the zip directory.

   Two new action codes have been added to the Progress Event.  use the
   values you get from these callbacks instead of the GetTotalFileSize
   method introduced in v1.45.  These values are calculated in the DLLs,
   and they should be more accurate than the GetTotalFileSize method.
      TotalFiles2Process - the "FileSize" arg tells you how many files will be
         processed by this operation
      TotalSize2Process  - the "FileSize" arg tells you the total size of all
         files to be processed by this operation

   New SFX changes for this release:
    - copyright info is now hidden under the "About" button
    - the "Shell Browse for Folder" API is used to select a directory
    - a new SFXOption is SFXCheckSize.  By default this is on.  When on,
      the SFX code will do a quick Self-test before expanding the files.
      This detects the most common problem - where your .exe file has been
      cut short by an aborted download.

    NOTE: The SFX module has to be limited in size, and so we did NOT
    add support for disk-spanning to it.  You can, however, write your
    own setup program to re-assemble the pieces.  I recommend putting
    the files for disk1 into an SFX .EXE, and have it run your setup
    program after expanding those files on the user's hard drive.  Your
    setup program can then read the remaining disks.

   Also new in v1.50: we convert forward slashes in filenames to backslashes.
   We used to show you forward slashes because that's what Phil Katz (the
   inventor of pkzip) did, but we now show you the right slashes! Sorry
   Phil!


    There is a new requirement for programs that you write.  We have
    put most of our error messages put into a resource file.  You
    need to add the desired resource file to your project file.
    Simply add a line like this to your project file:

       {$R ZipMsgUS.res}

    You can see how this was done by checking Demo1's .DPR file.
    These are the languages we support at this time:

       ZipMsgBR.res - Brazilian (Portuguese)
       ZipMsgCZ.res - Czech
       ZipMsgNL.res - Dutch
       ZipMsgFR.res - French
       ZipMsgUS.res - English / US
       ZipMsgDE.res - German
       ZipMsgGR.res - Greek
       ZipMsgIT.res - Italian
       ZipMsgPL.res - Polish
       ZipMsgYU.res - Serbian (Yugoslavia)
       ZipMsgSP.res - Spanish
       ZipMsgTW.res - Taiwanese/Traditional Chinese
       ZipMsgRU.res - Russian
       ZipMsgCN.res - Chinese
       ZipMsgHU.res - Hungarian
       ZipMsgSW.res - Swedish
       ZipMsgMY.res - Malaysia

    If you would like to port these error messages to another
    language, please e-mail me right away!


   ----------------------------------------------------------------------
   Quick summary of changes in version 1.45:
   bug fixes:
      Correct the bug in DateTime setting of CopyFile method
      Correct misc bugs in the SFX code

   new BCB features:
      Update BCB support to work with BCB v3

   new Delphi features:
      Add new "Unattended" property - all errors go to OnMessage error handler
         if this property is set True
      A new Error code list is being distributed with this release (helpful
         if you want to use the Unattended property)
      Add new ability to create an .EXE file directly
      Add a new demo program (demo5) to demo creation of an .EXE file
      Add function "GetTotalFileSize" to let you determine how big
         all the files are before starting a zip operation
      Update Demo1 to show 2 progress bars in Add: one "overall progress"
         and one "per file progress"

   ----------------------------------------------------------------------

   Quick summary of changes in version 1.40:
   bug fixes:
       Correct filenames are now given in the "skipping encrypted file..."
         error messages.  Thanks to: Markus Stephany, [e-mail]

       The SFX module now extracts more than 1 passworded file in an
         archive.   Thanks to: Markus Stephany, [e-mail]

       Correct progress events now generated for extraction of
         uncompressed files.  Thanks to: Esa Raita, [e-mail]

   DLLDirectory property - allows manual specification of the dir
       used to hold ZIPDLL.DLL and UNZDLL.DLL.  Should NOT end
       in a slash.  This is an optional property. if used, it overrides
       the Windows search path for DLLs.  If you specify a dirname
       here, but the DLLs are not actually in that dir, then the
       std Windows search path will be consulted.
          The idea for this came from Thomas Hensle, [e-mail].

   In case SFXPath isn't set, DLLDirectory will also be consulted
   when trying to locate ZIPSFX.BIN.  Here's the order that will
   be used to locate ZIPSFX.BIN:
         1) location given by the SFXPath property
         2) the current directory
         3) the application directory (location of current .EXE file)
         4) the Windows System directory (where DLLs go)}
         5) the Windows directory (where DLLs go)
         6) location given by the DLLDirectory property

   These are the advanced options for creating more powerful Self-Extracting
   archives.  By using these options, you can turn the new .EXE archive into
   a small Self-contained setup program!

   The following three boolean options are set members of SFXOptions:

   SFXAskCmdLine     boolean   (only matters if a cmd line is present)
        If yes, allows user to de-select the command line checkbox.
        Once deselected, the command line will not be run.
        NOTE: The checkbox doesn't appear unless there is a command line
        specified.

   SFXAskFiles       boolean   (if yes, lets user modify list of files
        to be extracted)

   SFXHideOverWriteBox   boolean  (if yes, does NOT show the user the
        dialog box that lets him choose the overwrite action at runtime for
        files that already exist)

   SFXOverWriteMode  enum     dflt=ovrConfirm  (others: ovrAlways, ovrNever)
        This is the dflt overwrite option (if SFXHideOverWriteBox is true, then
        this option will be used during extraction)

   SFXCaption        String   dflt='Self-extracting Archive'
        Caption of the SFX dialog box at runtime.

   SFXDefaultDir     String   dflt=''
        Default target dir for extraction.  Can be changed at runtime.
        If you don't specify this, the user's current directory will
        be the default.

   SFXCommandLine    String   dflt=''
        This command line will be executed immediately after extracting the
        files.  Typically used to view the readme file, but can do anything.
        There is a predefined symbol that can be used in the command line
        to tell you which target directory was actually used.
        Special symbols: | is the command/arg separater
                        >< is the actual extraction dir selected by user
        Example:
           notepad.exe|><readme.txt
        Run notepad to show "readme.txt" in the actual extraction dir.

  ------------------------------------------------------------------------

   TZipMaster is a non-visual VCL wrapper for my freeware ZIP and
   UNZIP DLLs.  At run time, the DLL's: ZIPDLL.DLL and UNZDLL.DLL must
   be present on the hard disk - in C:\WINDOWS\SYSTEM or else in your
   application directory, or a directory in the PATH.

   These DLLs are based on the InfoZip Official Freeware Zip/Unzip
   source code, but they are NOT equivalent to InfoZip's DLLs.
   I have modified the InfoZip source code to enhance their
   ease-of-use, power, and flexibility for use with Delphi and
   C++ Builder.  Please do NOT contact InfoZip for issues
   regarding this port.

   To obtain the official InfoZip source code, consult their
   Web site:
               http://www.cdrom.com/pub/infozip/

   The six main methods that can be invoked are:
       Add      - add one or more files to a ZIP archive
       Delete   - delete one or more files from ZIP archive
       Extract  - expand one or more files from a ZIP archive
       List     - transfer "table of contents" of ZIP archive
                  to a StringList

       CopyFile - copies a file

       GetAddPassword  - prompt user for a password - does verify
       GetExtrPassword - prompt user for a password - does NOT verify

   NOTE: "Test" is a sub-option of Extract

   All of the methods above will work on regular .ZIP files, and
   on Self-extracting ZIP archives having a file extension of .EXE.

   Various properties exist to control the actions of the methods.

   Filespecs are specified in the FSpecArgs TStringList property, so you
   can easily combine many different filespecs into one Add, Delete, or
   Extract operation. For example:

      1. Add entries directly to the FSpecArgs property:
          ZipMaster1.FSpecArgs.Add( 'C:\AUTOEXEC.BAT' );
          ZipMaster1.FSpecArgs.Add( 'C:\DELPHI\BIN\DELPHI.EXE' );
          ZipMaster1.FSpecArgs.Add( 'C:\WINDOWS\*.INI' );
          ZipMaster1.FSpecArgs.Add( 'SYSTEM\*.DLL' );

      2. Take the filespecs from a StringList, just assign them all over
         to ZipMaster1.
       ZipMaster1.FSpecArgs.Assign(StringList1);

      3. Take the filespecs from a ListBox, just assign them all over
         to ZipMaster1.
       ZipMaster1.FSpecArgs.Assign(ListBox1.Items);

   You can specify either the MS-DOS backslash path symbol, or the one
   normally used by PKZIP (the Unix path separator: /).  They are treated
   exactly the same.

   All of your FSpecArgs accept MS-DOS wildcards.

   Add, Delete, and Extract are the only methods that use FSpecArgs.
   The List method doesn't - it just lists all files.


   Following is a list of all TZipMaster properties, events and methods:

   Properties
   ==========
     Verbose      Boolean     If True, ask for the maximum amount of "possibly
                              important" information from the DLLs.  The
                              informational messages are delivered to your
                              program via the OnMessage event, and the ErrCode
                              and Message properties. This is primarily used
                              to determine how much info you want to show your
                              "end-users" - developers can use the Trace
                              property to get additional infomation.

     Trace        Boolean     Similar to Verbose, except that this one is
                              aimed at developers.  It lets you trace the
                              execution of the C code in the DLLs.  Helps
                              you locate possible bugs in the DLLs, and
                              helps you understand why something is happening
                              a certain way.

     ErrCode      Integer     Holds a copy of the last error code sent to
                              your program by from DLL. 0=no error.
                              See the OnMessage event.  Most messages from
                              the DLLs will have an ErrCode of 0.

     Message      String      Holds a copy of the last message sent to your
                              program by the DLL.  See the OnMessage event.

     ZipContents  TList       Read-only TList that contains the directory
                              of the archive specified in the ZipFilename
                              property. Every entry in the list points to
                              a ZipDirEntry record.  This is automatically
                              filled with data whenever an assignment is
                              made to ZipFilename, and can be manually
                              filled by calling the List method.
                                 For your convenience, this VCL hides the
                              TList memory allocation issues from you.
                                 Automatic updates to this list occur
                              whenever this VCL changes the ZIP file.
                              Event OnDirUpdate is triggered for you
                              each time this list is updated - that is
                              your queue to refresh your directory display.

   ---------------------------------------------------------------------
   Each entry in the ZipContents TList is a ZipDirEntry record:

   ZipDirEntry = packed Record
     MadeByVersion               : Byte;
     HostVersionNo               : Byte;
     Version                     : WORD;
     Flag                        : WORD;
     CompressionMethod           : WORD;