Replacing files in CAB archives
- Thread starter kejpa
- Start date
What you want to do is to change the files while they are inside the CAB file? Why dont you just make the CAB file again?
... but now that you say that, I remember thinking how cool it would be if one could change the contents of a compressed file without compressing it again.
... but now that you say that, I remember thinking how cool it would be if one could change the contents of a compressed file without compressing it again.
No not Windows OS,Mike_R said:
I want to install Adobe Reader silently and without the user needing to interfer. In order to do that I need to change a few properties in one of the files (abcpy.ini) inside the selfextracting CAB archive.
Currently it looks like I have to extract all files, make the changes and ship all of the files instead of just a single one. Takes a whole lot of more place too
/Kejpa
I don't think you can get around that realistically. Compression works by substituting values with much-shorter-length tokens (just a few bits per token) The most frequent values get the shorter tokens.
The data you are adding likely is using some new values not already present in the table/dictionary, so they would need to be added to the table in addition to your data. You'd have to know where this table is and how it is setup. And then even "inserting" your data would be a very, very sensitive concept, slip on one bit and the entire file beyond the insertion point is completely corrupted.
Even if this were your own compression algorithm and you therefore knew how it worked extensively, you would still find it extremely hard to insert data like this, I think. I do think the only reasonable approach is de-compress, edit, and then re-compress, I'm afraid...
The data you are adding likely is using some new values not already present in the table/dictionary, so they would need to be added to the table in addition to your data. You'd have to know where this table is and how it is setup. And then even "inserting" your data would be a very, very sensitive concept, slip on one bit and the entire file beyond the insertion point is completely corrupted.
Even if this were your own compression algorithm and you therefore knew how it worked extensively, you would still find it extremely hard to insert data like this, I think. I do think the only reasonable approach is de-compress, edit, and then re-compress, I'm afraid...
This looks like a decent link:
http://www.annoyances.org/exec/show/article01-010
If not what you need, then I'd Google on "CAB Writer" or "Cabinet Files", etc...
http://www.annoyances.org/exec/show/article01-010
If not what you need, then I'd Google on "CAB Writer" or "Cabinet Files", etc...
Rick_Fla
Centurion
Cabinet SDK
mentions the CABview that is also mentioned in the link Mike_R provided. But if you wanted to build your own CAB tools, see if that help.
mentions the CABview that is also mentioned in the link Mike_R provided. But if you wanted to build your own CAB tools, see if that help.