Compression and archive format that stores one or more files into a single file, usually with a .zip file extension.

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73
votes
11answers
4k views

Can zipping a file break it?

I just asked someone to send me a zipped psd file. They declined, citing that zipping a file can break the fonts. I assumed zipping a file is perfectly reversible, hence why it is commonly used. I ...
70
votes
2answers
28k views

What is __MACOSX folder?

What are these __MACOSX folders I keep seeing in zip files made by people on OSX? Some take as much as 30% of the file. What program are producing these __MACOSX folder and how can mac users avoid ...
65
votes
8answers
57k views

Zip Linux - View files in archive

How can I view the files in a zip archive without decompressing it ?
64
votes
20answers
71k 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 ...
63
votes
8answers
172k views

Can you zip a file from the command prompt using ONLY Windows' built-in capability to zip files?

I have a batch file that outputs a text file. I thought it would be nice if I could zip it up too. This will be used in an uncontrolled environment, so I can't make assumptions about the presence of ...
51
votes
5answers
2k views

How to “unextract” a zip file?

I extracted a zip file into a non-empty folder. The zip file has lots of files and a deep hierarchy, that merged with the existing tree of the target directory. How can I remove the files and ...
34
votes
5answers
3k views

Why is a 7zipped file larger than the raw file? [duplicate]

Possible Duplicate: Why doesn't ZIP Compression compress anything? I tried 7zipping an .exe file but it actually became larger. Is this the expected result?
34
votes
7answers
82k views

How to restore Windows default Zip file functionality?

I recently lost the default file association for Zip files in Windows Vista (I think it happened when I uninstalled WinAce, but I can't be completely sure). How can I restore this association back to ...
32
votes
9answers
5k views

How to uncompress a 9GB file in Windows FAT32

I have a 2GB RAR file that contains a 9GB video file. I'm using a FAT32 file system. Now I want to unzip that file but after 4GB I get an error due to the FAT32 file size limit. Now I want to know ...
32
votes
5answers
38k views

Read the contents of a zipped file without extraction?

How can I see the contents of a particular file in an archive without extracting the .zip it is contained within? I'm using the Linux command line.
30
votes
2answers
19k views

How secure are password-protected zip files?

In modern zip utilities like 7zip, you can specify a password when creating a .ZIP file. But, how secure is this? What encryption algorithm(s) are used to secure password-protected zip files?
26
votes
1answer
39k views

Linux unzip command: Option to force overwrite?

I am writing a shell script that unzips a ZIP file into an existing hierarchy of files, potentially overwriting some of the files. The problem is that the unzip command asks for confirmation: replace ...
25
votes
4answers
19k views

Can you configure Windows to open JAR files like ZIP files without a 3rd party tool?

I'd like to be able to examine the contents of a JAR file without having to install Winzip or some other tool and without having to rename the file. Windows Explorer can open ZIP files just fine; is ...
23
votes
4answers
45k views

Create a tar file for compressing files and directories on Mac OS X

I'm new to Mac OS X and am not sure how to do this: I have three directories. I want to create a tar/zip file of them so that I can attach them to an email. Any ideas?
22
votes
7answers
38k views

Which is more efficient - tar or zip compression? What is the difference between tar and zip?

I'm working in Linux environment and want to know about tar and zip commands. Which is more efficient - tar or zip? I also need to know the differences between the tar and zip commands. Can anyone ...
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 ...
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 ...
20
votes
5answers
18k views

Compressing folders on a mac, without the .DS_Store

Is there anyway to get rid of the .DS_Store when compressing a folder on a mac? I work on a mac and send work to clients in zip format, but always get questioned on the .DS_Store folder inside them. ...
20
votes
6answers
15k views

On Linux/Unix, does .tar.gz versus .zip matter?

Cross-platform programs are sometimes distributed as .tar.gz for the Unix version and .zip for the Windows version. This makes sense when the contents of each must be different. If, however, the ...
19
votes
5answers
17k views

tar – extract discarding directory structure

unzip has a nifty option -j, whereby the directory structure of the archive is discarded, and all files are extracted into the same directory. Is there a way of making tar work in the same way? ...
19
votes
2answers
12k views

Is zip's encryption really bad? [closed]

The standard advice for many years regarding compression and encryption has been that the encryption strength of zip is bad. Is this really the case in this day and age? I read this article about ...
18
votes
7answers
14k views

How can I create a zip / tgz in Linux such that Windows has proper filenames?

Currently, tar -zcf arch.tgz files/* encodes filenames in UTF, so Windows users see all characters spoiled in filenames which are not english, and can do nothing with it. zip -qq -r arch.zip files/* ...
17
votes
4answers
17k views

terminal tool (linux) for repair corrupted zip files

I've a corrupt zip file. I've tried to repair it with zip -F file.zip and zip -FF file.zip but was not successful. Is there another terminal tool under Linux for repairing?
17
votes
5answers
13k views

Unix zip directory but excluded specific subdirectories (and everything within them)

I'm trying to zip a directory (on Unix via SSH) but I need to exclude a couple of subdirectories (and all files and directories within them). So far I have this: zip -r myarchive.zip dir1 -x ...
16
votes
1answer
9k views

Remove single file from zip archive on Linux

I have a zip archive (created automatically in a script with -j -r flags) and I would like to remove a single file from it. I tried as documented. zip -d "picture_43_9.jpg" gallery.zip but I get ...
15
votes
4answers
29k views

How to make 7-Zip faster

I normally use WinRAR over 7-Zip simply because it's faster and only a little less efficient with compression. I did a few tests on different filetypes and sizes comparing the 7-Zip and WinRAR default ...
14
votes
12answers
4k views

What's the advantage of using RAR's?

The RAR file format is somewhat new to me and I'm trying to understand why people are switching to it over the "zip" file format. What's so special about RAR's? My initial assertion is that it's a ...
13
votes
4answers
24k views

What UnRar utilities are available for Mac OS X?

I have been using UnRarX ( http://www.unrarx.com/ ) and it's free and works well, but often times I will download a rar file in the browser and click on it in the recent downloads lists which will ...
12
votes
1answer
15k views

How to list the contents of a zip along w/ file sizes and compression ratio via cmd line

How do I list the contents of a zip along w/ file sizes and compression ratio (or packed size) on osx w/ command line tools?
12
votes
1answer
242 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 ...
11
votes
4answers
27k views

Zipping folders and their contents into a .zip file in Linux

How do I make a .zip file that contains every file AND every folder in the directory?
11
votes
3answers
35k views

Does Windows 7 have unzip at the command line installed by default?

There is a zip/unzip option in the context menu so is it accessible from the command line?
11
votes
7answers
14k views

How to create a zip file compatible with Windows under Linux

I need to make a zip file available to all my Windows users visitors, so I naively produced a zip file with the Unix zip command (let's call it madeinlinux.zip). It opens successfully with WinRar or ...
10
votes
8answers
3k views

Does it take longer to download a zipped file than an unzipped file?

I once read somewhere that it takes longer to download a zipped file than an unzipped file of the same size, due to the nature of the zip file. Is this true or nonsense? edit: i'm speaking about ...
10
votes
2answers
9k views

Avoid unwanted path in Zip file

I'm making a shell script to package some files. I'm zipping a directory like this: zip -r /Users/me/development/something/out.zip /Users/me/development/something/folder/ The problem is that the ...
10
votes
7answers
10k views

7zip doesn't ask me for password for a zip I encrypted while double-clicking it

I just tried to encrypt a folder with 7zip by command line choosing a password but when double-clicking on the zip file, it shows me the files list without asking any password. Any other alternative ...
10
votes
1answer
2k views

How to stop 7-Zip from automatically downloading and opening a zip file in Chrome?

I have checked the "Ask where to save each file before downloading" option in Chrome settings yet after installing 7-Zip, every time I click on a link which targets a .zip file: chrome doesn't fire ...
10
votes
1answer
2k views

How to do “legacy” ZIP compression with 7zip?

We have an old application that requires zip files to be "legacy" format. I would really love to get rid of the adware ridden WinZip and use 7zip. However, I don't know which compression options and ...
10
votes
4answers
37k views

What are the best options to use when compressing files using 7 Zip?

I often have to gather log files and upload them to a central server (Owned by another company). The central server has a size limit of the file, so I am trying to create the smallest file possible ...
10
votes
2answers
2k views

NTFS alternate stream in compressed archive?

Does any of the major compressed archive formats in Windows (e.g. zip, rar, 7z) support NTFS alternate data stream?
9
votes
4answers
14k views

Best Secure Encryption for Zip Files via Linux

I want to use highly secure encryption for zipped files via Linux/Ubuntu using a command line terminal, what is the best command line tool to get this job done? zip -e -P PASSWORD file1 file2 file3 ...
9
votes
1answer
262 views

How did this ZIP file print to my command line when I extracted it?

I downloaded a font from www.fontspace.com today. It came in a basic .zip file and so I moved it into its own new folder to extract it (I'm tired of extracting things just to find that they were ...
9
votes
8answers
26k views

How do I reassemble a zip file that has been emailed in multiple parts?

I received 3 emails each containing part of a zip file. The extensions end in .z00, .z01 and .z02. (Emailed as such to get around the typical 10Mb attachment limit per email.) I have put all 3 files ...
9
votes
4answers
5k views

Is there a way to edit files inside of a zip file without explicitly extracting them first?

I sometimes need to make changes to a .zip or .jar file, so I usually move the file to /tmp, extract all the files with unzip, edit a few files, and then re-zip up the files. This works, but it can ...
9
votes
1answer
233 views

What is the practical value of redundancy in zip files?

How is redundancy implemented in zipping, and how do I benefit from it? I'd assume it consists of something like storing the lookup tables twice so a single defect does not invalidate the whole rest ...
9
votes
2answers
56k views

How to crack a password protected zip file

I recently downloaded a piece of software that came in a .ZIP archive, but the .EXE software inside of the archive had a password on it. The website that I would have gotten the password from closed ...
8
votes
2answers
5k views

View Contents of Archive in Mac OS X

Aside from unzip -l, do I have any non-command line options for viewing an archive's contents on Mac OS X?
8
votes
4answers
14k views

add password to existing zip file with 7zip

Is it possible to add a password to an existing zipfile with 7zip without going to all the trouble of unpacking it and re-packing it again?
8
votes
2answers
36k views

In Ubuntu, how to copy all contents of a folder to another folder?

I want to copy the contents of an unzipped folder, wordpress/, to another existing folder. I tried cp -R wordpress/*.* /my/folder but the sub-folders in wordpress/ didn't get copied over. Why ...
8
votes
1answer
6k views

ZIP file decompression inflating vs extracting

I used the cPanel control panel to extract image archive. While decompressing it displayed a list of all files with information like inflating filename... or extracting filename... I noticed that ...