Abbrevia or other good compression library?

[el3ctrolyte]

Hey everyone! I want to write a program that needs to use compression. I know that fpc comes with libraries for this, but they are limited. Basically i want to be able to extract just one file form the zip but the libraries included in fpc doesn't have this feature. Abbrevia seems to be the library that i should use, but the fpc/lazarus version hasn't been updated in ages. And the delphi version is pretty up to date. Is there a other library that i can use? or is there a newer version of abbrevia available?

[lucamar]

Basically i want to be able to extract just one file form the zip but the libraries included in fpc doesn't have this feature.

What do you mean? You can do it perfectly with TUnzipper, using Unzip() or UnzipFile ...

Anyway, I think you can use the normal Abbrevia (the one at SourceForge): IIRC most of TurboPower packages were modified to be usable also with Lazarus, not only Delphi, to avoid having special, Lazarus-only forks.

[el3ctrolyte]

Ahh i misspoke! Sorry. What i meant was i wanted to add a file to an existing zip file. Can i do this with what is included in lazarus/fpc?

[lucamar]

Ahh i misspoke! Sorry. What i meant was i wanted to add a file to an existing zip file. Can i do this with what is included in lazarus/fpc?

Yes, of course: TZipper class, methods Zip() or ZipFile()

[el3ctrolyte]

Are you sure. I know how to make zip files, but i want to add files to an existing zip file that already has files in it without extracting the zip file and then recompressing it. Maybe you can give me a code sample that shows how to add a file to an existing zip file that already has files it it.

[lucamar]

I'm a tiny bit busy ATM (it's supper time here around), but I'll try to do it in the next couple hours, OK?

[lucamar]

Ok, it seems you were right, sorry

I made a very quick, simple test and TZipper always overwrites the archive, adding only those files you add to it in the moment. I kind of remembered we using it to update an archive but if so it must have been after some heavy modifications

It looks like you'll have to either complicate your (programming) life or just use Abbrevia, which works quite well ... at least it did last time I used it, though that was with Delphi

[jcmontherock]

Find Abbrevia 5.2 taken from CodeTyphon.

[el3ctrolyte]

The latest delphi version from github is 10.4.1
https://github.com/TurboPack/Abbrevia

[jcmontherock]

In fact it's a 6.91 version as written in lpk file (?).

[avra]

Find Abbrevia 5.2 taken from CodeTyphon.

I did not put it into ct4laz and OPM because there is already FPC version available here: http://tpabbrevia.sourceforge.net

In fact it's a 6.91 version as written in lpk file (?).

No, that is version of CodeTyphon in which it was last updated.