Poll Zip files formats

[Artlav]

Time and again i find that my ways of using a computer are not the same as the common ones. Now a project i am contemplating involve parsing ZIP files.

So comes the poll:
How do you make a ZIP files?
What kinds of ZIP file formats are out there?

If you want to help, please pack a few files into a zip (not too big, just non-empty archive), and send it over to me (for example by uploading here: orbides.1gb.ru/fsnd.php , not needed any more )
Also, provide a description of the method used (i.e. WinZip, compressed folder, 7zfm, Total commander, etc).

 

[Turbinator]

On the rare occasion that I do have to reduce the size of some files I use 7zip and the .7z compression. It has the highest compression ratio I have ever encountered. There was a 1.6 Gb program that was squeezed in to 700Mb with it.

If I have to collect a few files together to send over email, like pictures, I just use the .zip format. This is because it is now integrated with windows, and people without tech skills can open them.

 

[MaverickSawyer]

I only use the standard Windows Zip.

 

[Axertan]

Time and again i find that my ways of using a computer are not the same as the common ones. Now a project i am contemplating involve parsing ZIP files.

So comes the poll:
How do you make a ZIP files?
What kinds of ZIP file formats are out there?

If you want to help, please pack a few files into a zip (not too big, just non-empty archive), and send it over to me (for example by uploading here: http://orbides.1gb.ru/fsnd.php )
Also, provide a description of the method used (i.e. WinZip, compressed folder, 7zfm, Total commander, etc).

Okay, I sent you a .zip archive through your upload link. A readme file with the settings I used to archive it is included in it.
Good luck with the project!

 

[orb]

In Windows, for personal purposes I almost exclusively use 7z file format and Lempel-Ziv-Markov chain compression (LZMA or LZMA2) in "Ultra" mode with 256-bit word size (and 64MB dictionary, and optionally "tm=on tc=off ta=off mc=1024" additional arguments), but if I need to make a zip file (for example to embed it into a post on Orbiter-Forum, or send via e-mail to somebody who doesn't know what 7z file is), I create it with 7-zip (usually 7zG shell extension) with Deflate algorithm, 32KB dictionary, 256-bit word size, and "tc=off pass=15" additional arguments.

If if find some data to compress (a part of Orbiter folder probably), I'll upload a zip file made that way.

Note that zip format supports too Deflate64, BZIP2, LZMA and PPMd compression algorithms, but standard Windows compressed folders extension doesn't support (most or some of) them (but rather only stored, Imploded, or Deflated files).

In Linux I don't use zip files for making archives at all, but only xz (LZMA2) compressed tarballs.

 

[Spacethingy]

:theysaid:

I go for 7zip, it seems way quicker than the built in Windows zipper/dezipper.

Does anyone use RAR? I can't find a program to actually make RARs, only deflate 'em.

 

[Tommy]

Winrar is the best tool to create .rar files. Rar is less common in the US, so many people don't know how to open them.

A big advantage to Rar is that the archive can be broken into small segments for easier downloading on a slow connection. Doug uses that for the XR series, for people with slow connections.

 

[orb]

Does anyone use RAR? I can't find a program to actually make RARs, only deflate 'em.

RAR is a proprietary closed source format, so to create rar archives you need (most likely) a commercial software which uses RAR compression license ([ame=http://en.wikipedia.org/wiki/RAR]Wikipedia[/ame]: "RAR for Pocket PC is the only freeware for creating RAR files"). So, like Tommy said Winrar is the best tool to create .rar files under Windows. Only decompression algorithm of RAR is free of charge, so most archivers can extract rar archives, but not create them.

archive can be broken into small segments for easier downloading on a slow connection.

This is not advantage over other formats, as many of them support creating multi-volume archives (archives split into segments) too, like for example 7z format (and zip too).

 

[Artlav]

The point of the poll was to collect samples of ZIP files, since the specs allow for many variations and a few uncertainties.
The statistics on other archivers is useless, since most Orbiter add-ons are in ZIP form.

Anyway, there is no need to continue - on one hand, i realized that i can get all the samples i need on OH, of which i keep a local mirror, on the other hand, the project in question turned out to have extreme work-to-result ratio at microscopic usefulness (modding Orbiter to use add-ons from zips directly), so the research no longer concerns this community.

 

[nickwelhar]

Zip

Generally speaking most modern compression algorithms give roughly the same compression, and with regard to the number of cores that you can use at once, it is up to you to decide how many you want to use. "zip" in this context is a file format that permits several different compression methods. They include deflate, deflate64, bzip2, lzma, wavpack, and ppmd. In practice however, you will almost always see deflate used exclusively in zip files, for compatibility. DEFLATE is used to compress GZIP files. This algorithm is implemented efficiently in 7-Zip. We can turn the "fast bytes" and "number passes" knobs to optimize the algorithm. This influences DEFLATE compression in 7-Zip.