Contents - Index - Previous - Next
SaveZipInfoOnFirstDisk property
Applies to
Declaration
property SaveZipInfoOnFirstDisk: Boolean;
Description
This property determines whether VCLZip will save a special Zip Configuration File on the first disk of a spanned zip file, when creating a spanned zip file (this works for blocked zip files too - that is spanned zip files created directly to your hard drive). This will allow VCLZip to open the spanned zip file from the first disk of the set instead of requiring the last disk to be inserted.
Normally, PKZip compatible spanned zip files require that the LAST disk of the disk set be inserted first in order to open up the zip file. This often creates confusion and is an annoyance. VCLZip has the unique capability to create and read spanned zip files which will allow VCLZip to open a spanned zip file from the first disk. This option does not cause the spanned zip file to be non-PKZip compatible as PKZip, WinZip, and all of the other zip utilities can still open and read the spanned zip file normally (from the last disk). However, VCLZip will, if this option is set to True, write some extra information onto the first disk in a separate file. VCLZip will detect this file if the first disk is inserted first, and read from it, the information it would otherwise need the last disk to obtain.
If this property is set to True before calling the Zip Method to create spanned zip file, then when the zip file has been completely created, VCLZip will ask you to re-insert the first disk of the spanned zip file. VCLZip will then write out a special file called a Zip Configuration File which will be named the same as your zip file except it will have an extention of '.ZFC'. If this first disk is ever the first disk inserted when trying to open up the zip file (which is a common mistake among users), VCLZip will automatically detect this file and use the information from it to get the contents of the spanned zip file.
Note that other zip utilities will not be able to make use of this feature, only VCLZip will be able to use this file.
IMPORTANT: VCLZip will attempt to save enough room on the first disk to allow for the Zip Configuration File to be written. This amount will be added to the SaveOnFirstDisk property in the case of writing directly to removable media (MultiZipMode = mmSpan) or subtracted from the FirstBlockSize property in the case of creating the spanned zip file directly to the hard drive (MultiZipMode = mmBlocks). If you are storing file comments, fairly long filenames, or longer than usual path information, you may find that you might need to adjust the SaveOnFirstDisk or the FirstBlockSize property ahead of time to compensate for this somewhat.
Basically the size of the Zip Configuration File, in bytes, will be approximately:
( Total Number of files * 46) + length of all filenames (including path information if saved) + length of each file comment + 22 + length of the zip comment.