0
votes
0answers
34 views

Sequential Compression of [Text] Files (7zip and Windows)

This is with Windows 7. I have an iterative process, and on each iteration it produces a text file. What I want to do is compress this text file on each iteration to an archive. I'm using vb.net and ...
11
votes
2answers
436 views

Compressing many similar big files

I have hundreds of similar big files (30 megabyte each) which I want to compress. Every pair of files have 99% of same data (less then 1% difference), so I expect to have not more than 40-50 megabyte ...
1
vote
0answers
67 views

Re-zip archives with the compression level “No Compression”

I am running Windows 8.1 Enterprise x64. I have a folder containing hundreds of ZIP archives (aka Compressed folders). I need the fastest way to convert them (preferably, in-place) to vaild ZIP ...
4
votes
2answers
113 views

How can I specify the order files should be compressed in 7zip?

I have a set of files I would like to compress that I know to be repetitive and compressible, but 7zip chooses a non-optimal order to compress the files and fails to take advantage of their ...
3
votes
1answer
100 views

Is there a way to compress files at different compression levels inside a single 7zip file? [duplicate]

Some files are compressed using their own compression scheme and some aren't. If I try Max compression on an already compressed file, I'll get 1%-2% better compression at most. The amount of time ...
0
votes
0answers
94 views

New versions of srep failing my compression algorithm

I am currently using freearc, precomp042 and srep 3.2 (32bit) I am running on Windows 7 SP1 x64 with 8GB RAM I use 4 regular compressions styles as noted below depending on data type and have no ...
2
votes
2answers
103 views

What other archive formats save Date Created and Date Accessed?

7-Zip on Windows will save the Date Created and Date Accessed when compressing a .zip file, however it does not do this for its native .7z format. Any Unix-based formats are ineligible. Are there any ...
0
votes
0answers
126 views

How can I get RAR to create a segmented archive (volumes) when compressing from stdin?

I have this ZFS box where I'm creating incremental snapshots, then piping them into RAR (4.2) for compression and encryption, and finally backing those files up remotely. Thing is, RAR seems to ...
0
votes
1answer
983 views

Can't view files from within WinRar (Win7 x64)

I have an issue with WinRar (64 bit version) on Windows 7 (x64) that is similar to the one described in another open question on this website Link to the same issue on this site (unanswered) However, ...
1
vote
0answers
1k views

“extra bytes at beginning or within zipfile,” won't open file

I have an 8.3 gig zip containing tons of telescope observation data, but I can't extract no matter what I try. I've tried Archive Manager, unzip, and tried this guy's fix: ...
2
votes
4answers
8k views

Compress a 1GB file into 200_MB?

So I just downloaded MySQL for Windows 64bit which 211.9MB but when I extracted it it is now 1.05GB. How did they do it? They archive wasn't damaged at all nor corrupted. Before (Compressed): ...
1
vote
2answers
1k views

Synchronizing files using 7zip and the CLI

In the command line, 7zip has the command 'a' to "Add files to archive". But I want to sync the files instead. This is one of the main options in the GUI, but the CLI has disregarded it for some ...
1
vote
2answers
253 views

Compressing multiple files into multiple archives?

I have a folder full of pdfs and I'm tired of Winraring each file separately. I don't want to put them all in one archive. Isn't there a command line I can use to make Winrar compress a file with ...
1
vote
0answers
41 views

Archive / compression formats or tools which support multiple file forks or streams?

Lately I've become interested in the ability of several filesystems including Apple's HFS+ and Microsoft's NTFS which support two or more data streams. In Mac terminology these were most widely ...
0
votes
3answers
5k views

How to compress / reduce the size of JPEG photos for archiving? [closed]

I have 50,000 high resolution JPEG photos, where a couple of them might occasionally be needed, about once a year. I wanted to zip them to save disk space, except that zipping gives no space benefit ...
7
votes
5answers
3k views

Whatever happened to compressed read/write filesystems?

Back in the 90s, my home computer was an Acorn Archimedes. It had on it a piece of software called ArcFS, which allowed you to create compressed archives, a bit like zip files. Unlike zip files, they ...
0
votes
2answers
1k views

Advanced file compression software for Mac OSX

Back when I used Windows, I always used WinRAR for file compression and decompression. It had a fair amount of options like 'just storage' vs 'hard compression', password protection and archive type. ...
0
votes
5answers
3k views

Zip multiple folders indvidually, automatically

I have folders full of photos within category folders eg holidays spain france italy family son daugher christmas 2010 2011 ... except much longer ... there are about 100 folders. I need ...
20
votes
4answers
2k views

Can Double Zipping Cause Problems?

I have a directory that I have been storing a ton of files in. Among the 10ish types of files there are also .zips of other directories. In my personal experience I vaguely remember issues when ...
3
votes
2answers
1k views

Does the RAR compression algorithm compress better than the ZIP compression algorithm?

I took 3 test files and ZIPped them. With the 3 test files again I RARred them. Each .RAR archive is smaller than the corresponding .ZIP archive. Does the RAR compression algorithm give a better ...
22
votes
6answers
3k views

How can I evaluate the best choice of archive format for compressing files?

In general, I've observed the following: Linux-y files or tools use bzip2 or gzip for distributing archives Windows-y files or tools use ZIP for distributing archives Many people use 7-Zip for ...
0
votes
2answers
882 views

Archive format & tool for large amounts of data (50gb+)

I only realised this afternoon that the ZIP format has a limit of what appears to be around 20gb. I am trying to automate an archive process (using Automate) to zip/rar/whatever a collection of ...
4
votes
2answers
283 views

Unix/Linux program that can handle all popular compression/archiving formats (e.g.tar, gzip, bzip2, zip)?

I sometimes get confused by the varying command line options I need to run common Unix archiving and compression software (e.g. gzip, bzip2, zip, tar). Is there a program out there that can just Do ...
2
votes
3answers
213 views

tar-ing / should I use -C / . or just /

tar cvf backup.tar -C / / # or tar cvf backup.tar / produces an archive like etc/ and gives warnings tar: Removing leading `/' from member names tar: Removing leading `/' from hard link ...
1
vote
1answer
850 views

How can I updated an encrypted 7zip archive without losing encryption?

I created a 7zip archive with AES encryption. I included the option to encrypt the filenames. When I updated the file however I am no longer prompted for a password to open the file and can view the ...
8
votes
2answers
25k views

How to set password on already existing winrar archive and encrypt it also?

Not when creating new archive, but on existing archive. I would also like to know how to do that in other archiver.
0
votes
1answer
173 views

OS X compressed files on a Windows machine

I sent myself a compressed folder from my OS X machine to my Windows machine. When I opened it I of course got the __MACOSX folder, but the contents were in an extension-less file of about the right ...
2
votes
1answer
533 views

Archiving large folders

I'd like to create a (compressed) archive of a folder which contains ~350,000 items totalling ~17 GB. Is .tar.gz a sane format to use, or would .zip, .rar, or .7z work better for handling that much ...
4
votes
1answer
1k views

Compressed disk image on Linux

I just got my new computer with a much bigger harddisk. I think I copied all important files over but just to be sure, I'd like to keep a disk image of my old disk. To save space, I'd like to compress ...
2
votes
4answers
879 views

How to get 100% identical compressed files, for source files that only differ in creation date?

I want to be able to compress a file losslessly, and if the original file is identical to another user's file, I want both of our compressed files to match, even if the original file dates are ...
2
votes
3answers
963 views

Browsable compressed filesystem archive with full attributes?

Maybe a variation of the whole question would be: Are there any other archiving tools than tar that preserve Linux file permissions and user/group flags? I want to create archives of a directory tree ...
1
vote
1answer
986 views

Tar xvzf question

Hi I use FC12 command : tar xvfz GeoIP.dat.gz I get the errors tar: This does not look like a tar archive tar: Skipping to next header tar: Error exit delayed from previous errors Whats the ...
2
votes
2answers
2k views

Creating/extracting RAR files on Mac OS X

I would like to be able to create RAR files easily on Snow Leopard with some sort of GUI utility. I know that RARlabs maintains a Mac version of the RAR command line utility, but I don't want to have ...
0
votes
2answers
2k views

“Unsupported compression method 98” error when unzipping a file. What tools support it, other than WinZip?

I'm getting an error message: "unsupported compression method 98" when unzipping a file somebody sent to me. I've tried both an older version of WinZip, and 7-Zip 4.65. (Update: I've also tried ...
13
votes
2answers
5k views

How does file compression work?

So, I realised today I take file compression for granted. The ability to bundle a few files together into one, and have it come out smaller than any of them, is something I just accept as a fact, but ...
12
votes
1answer
239 views

Three formats? Why?

I needed to download the Ruby Source recently from here and it says, "available in three formats" which are .tar.bz2, .tar.gz and .zip. Is there any reason that we need all three formats? At least on ...
2
votes
3answers
11k views

How can I remove the password protection from a RAR archive? [duplicate]

I have a directory in which there are lots of password protected .RAR files/archives. The passwords of these individual archives are known. I want to remove the password protection from all of them ...
5
votes
8answers
4k views

Winrar-like archive utility for OS X

I've been a Mac user for about 1.5 years and so far enjoyed the experience. But one thing I miss from other operating systems is the lack of compression/decompression utilities that follow the ...
0
votes
1answer
394 views

Compress and Upload vis SSH?

Is it possible to compress several folders and upload to another location (ftp) remotely? I've a GoDaddy account with SSH access, and I'd like to create a backup (zip all folders) and upload directly ...
37
votes
8answers
40k views

What’s a good way to extract .rar files on the Mac? [closed]

Anything built-in? (E.g. command line tools.) Any well-regarded software? Update: I like The Unarchiver, but vote up your favourite, or add it as an answer if it isn’t there.
0
votes
6answers
1k views

A compression program that handles files with unusual extensions

WAR files are simply ZIP files with a renamed extension. I'd like to configure a compression program to handle these (on double-clicking the file), but mine doesn't recognize them unless I rename them ...
0
votes
2answers
206 views

Compressed Folder Wizard - other archive formats

Anybody know of a shell extension to make other archive formats, such as RAR, work with Windows' built-in Compressed Folder Wizard?
62
votes
20answers
65k views

Compressing with RAR vs ZIP

A lot of people are compressing files with RAR, sending compressed files with RAR and so on. ZIP is more standard and works on all platforms. Windows users have ZIP included and Linux users have no ...