Why is this zip file unable to open?

Question

I'm trying to unzip a zip file which contains a video... right away it says:

7-Zip [64] 9.20 Copyright (c) 1999-2010 Igor Pavlov 2010-11-18 p7zip Version 9.20 (locale=en_US.UTF-8,Utf16=on,HugeFiles=on,2 CPUs)

Error: /home/cyberproxy/Downloads/Floating1a.zip: Can not open file as archive

Errors: 1

Unzips on my Android, unzips on my Windows desktop, unzips on my mother's iOS device with unzipper app.

What can I do to fix this?

Does the file unzip on another system?
It seems like you may have a corrupt file. — RolandiXor, Jun 13 '14 at 16:04
Unzips on my Android, unzips on my Windows desktop, unzips on my mother's iOS device with unzipper app. — Mike Wentworth, Jun 13 '14 at 16:05
When comments ask for clarification, always [edit] that clarification into the answer, then comment (with @name to the person) to say that you have done so. Comments are often unread, and may be deleted. Also, in general, it's better for a question to be self-contained, rather than relying on comments. — TRiG, Jun 13 '14 at 16:06
hm, can p7zip handle a .zip file? shouldn't you be using unzip? or is it a 7zip file with a .zip extension? — roadmr, Jun 13 '14 at 16:37
@roadmr Yes this is compatible. From the man page of 7z: "7-Zip is a file archiver supporting 7z (that implements LZMA compression algorithm featuring very high compression ratio), LZMA2, XZ, ZIP, Zip64, CAB, RAR (it was removed due a non-free license), ARJ, GZIP, BZIP2, TAR, CPIO, RPM, ISO, most filesystem images and DEB formats. Compression ratio in the new 7z format is 30-50% better than ratio in ZIP format. 7z uses plugins to handle archives, so it might be slightly slower than 7za(1) but can handle more archive formats." — David Tonhofer, Feb 10 '18 at 22:14

Marty Fried · Answer 1 · 2014-06-13T16:32:24.940

3

Try downloading p7zip-full from the standard repository.

"p7zip-full provides utilities to pack and unpack 7z archives within a shell or using a GUI (such as Ark, File Roller or Nautilus)."

EDIT: It seems that newer versions of File Roller can open 7Z files automatically, according to the installation notes.

edited Jun 13 '14 at 16:32

answered Jun 13 '14 at 16:09

Marty Fried

18,466

Please add instructions on how to use it (less experienced users who wouldn't have a clue what to type). – RolandiXor Jun 13 '14 at 16:10
Once installed, "p7zip-full provides utilities to pack and unpack 7z archives within a shell or using a GUI (such as Ark, File Roller or Nautilus)." IE, It will work just like normal zip, no extra commands required. – Marty Fried Jun 13 '14 at 16:11
It says it's already been installed. Weird. – Mike Wentworth Jun 13 '14 at 16:15
In that case, are you sure that the copy on Ubuntu is exactly the same as the one you can open successfully? Perhaps it got corrupted. Or, check permissions to make sure you have permissions (check owner and permissions in properties). – Marty Fried Jun 13 '14 at 16:23
Yup! Same copy [Bluetooth transfer]. Nothing seems off about the permission. I just installed Kubuntu and it opened the zip instantly -- although nothing was in it, it still unzipped. – Mike Wentworth Jun 14 '14 at 03:34
nothing was in it? Why is that? If nothing is in it, then what's the point? And if something is in it, then how can you say Kubuntu unzipped it? Also, how did you verify that the copy is the same? Just because it's a Bluetooth transfer doesn't make it the same - there could have been an error, and one little error on a compressed file is enough. – Marty Fried Jun 14 '14 at 17:03

score 2 · Answer 2 · answered Jun 13 '14 at 16:07

2

My first thought is that the archive is not properly formatted as such. The unzip program doesn't think that it's a valid zip file.

Try opening a terminal (search for it in your programs menu). For the purposes of this demonstration, I'm going to assume it's in your downloads folder.

Once you've opened the terminal do the following:

Change directory to the downloads folder.

cd ~/Downloads
Unzip the file using the command-line tool, unzip

unzip Floating1a.zip

This should put it into a folder (or give you a zip-bomb in the current directory) of everything that's in it. If this fails, it is almost guaranteed to be a problem with the file, not the unzip program.

answered Jun 13 '14 at 16:07

Mitch

4,697

It still didn't work -- what I don't understand is how an Android device can open it but a real Linux machine can't. I'm baffled. – Mike Wentworth Jun 13 '14 at 16:12
7z format is a newer format, and not a standard zip format. It is probably a licensing issue, but the required addon is freely available from the Ubuntu repository, as are other non-standard formats. – Marty Fried Jun 13 '14 at 16:19
But that still doesn't explain why Android can do it. Although I understand you, – Mike Wentworth Jun 13 '14 at 16:23
2

I'm wondering if it's not really zipped at all and the other sources are recognizing this and opening it as it should be opened (in a media player)? try opening it with VLC or whatever program you have installed for media. – Mitch Jun 13 '14 at 16:25
On further investigation, I see that on my system (xubuntu), file-roller has the ability to open 7z files. But the previous suggestion might also be good. BTW, Android != Linux; it is only built on parts of the Linux Kernel. I doubt that Linux includes this ability anyway, though. – Marty Fried Jun 13 '14 at 16:28
I know that Android is Linux, that's why it's surprising Android has more power than "Ubuntu" Linux. In various respects like this one. I'll try Xubuntu. – Mike Wentworth Jun 13 '14 at 18:32
Xubuntu won't make a difference, I don't think, because it uses File Roller, same as Ubuntu. I was saying Android is not Linux; technically, Ubuntu really isn't either. Both use a version of the Linux Kernel, but the kernel is not an app or a GUI, it is just used by apps and guis (and distros). – Marty Fried Jun 14 '14 at 16:59

Why is this zip file unable to open?

2 Answers2

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