How do I zip a directory of files using C++?

Question

I'm working on a project using C++, Boost, and Qt. I understand how to compress single files and bytestreams using, for example, the qCompress() function in Qt.

How do I zip a directory of multiple files, including subdirectories? I am looking for a cross-platform (Mac, Win, Linux) solution; I'd prefer not to fire off a bunch of new processes.

Is there a standard way to combine bytestreams from multiple files into a zipped archive, or maybe there is a convenience function or method that would be available in the Boost iostream library?

Many thanks for the assistance.

Update: The QuaZip library looks really great. There is an example in the download package (in the "tests" dir) that shows very clearly how to zip up a directory of files.

Update 2: After completing this task on my Linux build environment, I discovered that QuaZip doesn't work at all with the Visual Studio compiler. It may be possible to tackle all those compiler errors, but a word of caution to anyone looking down this path.

Answer 1

I tried QuaZIP 0.4.3 on Windows with VisualStudio 2010 -- there are still issues but can be resolved easily.

To build with VS:

1. Use CMake to configure and generate VS solution for QuaZIP.
2. Open soltion with VS and build -- you'll first notice that it can't find 'zlib.h'.
3. Open preferences for quazip project and add path to Qt's copy of Zlib to C/C++->General->Additional Include Directories: $(QTDIR)/src/3rdparty/zlib.
4. Rebuild again and you'll get lots of warnings and one error C2491: dllimport static issue on QuaZipFile::staticMetaObject.
5. This is because QuaZipFile is declared like "class QUAZIP_EXPORT QuaZipFile" and QUAZIP_EXPORT needs to resolve to Q_DECL_EXPORT for dll and to Q_DECL_IMPORT for application, based on whether QUAZIP_BUILD is defined or not. When building QuaZIP QUAZIP_BUILD should be defined but isn't -- configuration process defines in error completely useless "quazip_EXPORTS" instead.
6. To fix, just remove "quazip_EXPORTS" from all build configurations and add QUAZIP_BUILD instead -- QuaZIP will now build fine.

Answer 2

I have found the following two libraries:

• ZipIOS++. Seems to be "pure" C++. They don't list Windows explicitly as a supported platform. So i think you should try your luck yourself.
• QuaZIP. Based on Qt4. Actually looks nice. They list Windows explicitly (Using mingw). Apparently, it is a C++ wrapper for [this] library.

Ah, and of course, i have ripped those sites from this Qt Mailinglist question about Zipping/Unzipping of directories :)

Answer 3

Just for the record...

Today, I needed to do something very similar in Visual C++. (Though wanted to maintain the possibility to compile the project on other platforms; however preferred not to adopt Qt just for this purpose.)

Ended up using the Minizip library. It is written in plain C, but devising a simple C++ wrapper around it was a breeze, and the end result works great, at least for my purposes.

Answer 4

system("zip myarchive.zip *");

Answer 5

I have built a wrapper around minizip adding some features that I needed and making it nicer to use it. Is does use the latest c++11 and is developed using Visual Studio 2013, so it should work out-of-the-box for you.

There's a full description here: https://github.com/sebastiandev/zipper

you can zip entire folders, streams, vectors, etc. Also a nice feature is doing everything entirely in memory.

Answer 6

http://www.zlib.net/