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

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120
votes
8answers
116k views

View files in ZIP archive on Linux

How can I view the files in a ZIP archive without decompressing it?
114
votes
9answers
11k views

Why is Zip able to compress single file smaller than multiple files with the same content?

Suppose that I have 10,000 XML files. Now suppose that I want to send them to a friend. Before sending them, I would like to compress them. Method 1: Don't compress them Results: Resulting Size: ...
92
votes
3answers
47k 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 ...
80
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 ...
76
votes
9answers
233k 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 ...
74
votes
20answers
96k 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 ...
67
votes
3answers
3k views

Windows File is ludicrously huge and I cannot unzip it

I use an online file backup service (Backblaze) and recently got a new computer. Several files on my old computer were too large to move via my usb drive so I decided to download them from my backup ...
58
votes
5answers
80k views

Read the contents of a zipped file without extraction? [duplicate]

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.
53
votes
5answers
3k 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 ...
46
votes
2answers
69k 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 ...
44
votes
7answers
112k 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 ...
36
votes
5answers
30k 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. ...
34
votes
5answers
6k 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?
33
votes
7answers
31k 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 ...
33
votes
2answers
22k 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?
32
votes
9answers
8k 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
4answers
65k 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?
31
votes
7answers
64k 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 ...
30
votes
6answers
23k 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 ...
30
votes
1answer
19k 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 ...
29
votes
4answers
23k 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 ...
26
votes
4answers
28k 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?
26
votes
8answers
24k 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 ...
24
votes
5answers
5k 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 ...
24
votes
2answers
26k 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?
24
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 ...
21
votes
5answers
26k 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? ...
21
votes
4answers
37k 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 ...
20
votes
2answers
17k 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 ...
20
votes
4answers
45k 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 ...
19
votes
7answers
19k 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/* ...
19
votes
4answers
59k 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?
19
votes
2answers
14k views

Is zip's encryption really bad?

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
3answers
63k 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 ...
15
votes
7answers
17k 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. Is there any way to ...
15
votes
2answers
31k views

How to unzip split files on OS X

How do I unzip a split zip file? In Terminal, I wrote: unzip filename.zip and it did not unzip this file. Terminal wrote: $ unzip filename.zip Archive: filename.zip warning [filename.zip]: ...
14
votes
12answers
5k 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 ...
14
votes
3answers
27k views

How do I create separate zip files for each selected file/directory in 7zip?

This is the internal zip packer from Total Commander: However I want to use my 7zip packer. When I select 5 files, I get 5 separate .zip archives for each selected file. How do I do that in 7zip?
14
votes
5answers
15k 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 ...
14
votes
8answers
58k 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 ...
14
votes
3answers
21k 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?
12
votes
5answers
10k views

How can I test all zip files in a folder to verify if they are corrupted or not?

There was a utility a long time ago called CFAtest that was doing this quite nicely, but it has disappeared. Basically, I am looking for a similar tool (preferably graphical) that will traverse a ...
12
votes
3answers
52k 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?
12
votes
1answer
251 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 ...
12
votes
6answers
22k views

How can I achieve the best, standard ZIP compression?

I don't care how long it takes to compress, all I want to achieve is two things: The absolute best possible compression ratio Compatibility with standard readers, such as Windows and WinZip So ...
12
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?
12
votes
1answer
6k views

How to overwrite existing zip file instead of updating it in Info-Zip?

To obtain a fresh zip file just like as tar does, do I have to perform rm foo.zip before executing zip? $ mkdir foo; touch foo/bar $ zip -r foo.zip foo adding: foo/ (stored 0%) adding: foo/bar ...
11
votes
8answers
5k 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 ...
11
votes
2answers
12k views

Compress files from OS X terminal?

In the Finder, there is this wonderful ability to right click on a file or directory, select compress from the drop-down, and end up with a zipped file. Is it possible to do the same thing from the ...
11
votes
1answer
4k 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 ...