unzipping a file in cocoa

Question

I have a zipped file, which i want to extract the contents of it. What is the exact procedure that i should do to achieve it. Is there any framework to unzip the files in cocoa framework or objective C.

Answer 1

If you are on iOS or don't want to use NSTask or whatever, I recommend my library SSZipArchive.

Usage:

NSString *path = @"path_to_your_zip_file";
NSString *destination = @"path_to_the_folder_where_you_want_it_unzipped";
[SSZipArchive unzipFileAtPath:path toDestination:destination];

Pretty simple.

Answer 2

On the Mac you can use the built in unzip command line tool using an NSTask:

- (void) unzip {
    NSFileManager* fm = [NSFileManager defaultManager];
    NSString* zipPath = @"myFile.zip";

    NSString* targetFolder = @"/tmp/unzipped"; //this it the parent folder
                                               //where your zip's content 
                                               //goes to (must exist)

    //create a new empty folder (unzipping will fail if any
    //of the payload files already exist at the target location)
    [fm createDirectoryAtPath:targetFolder withIntermediateDirectories:NO 
                                           attributes:nil error:NULL];


    //now create a unzip-task
    NSArray *arguments = [NSArray arrayWithObject:zipPath];
    NSTask *unzipTask = [[NSTask alloc] init];
    [unzipTask setLaunchPath:@"/usr/bin/unzip"];
    [unzipTask setCurrentDirectoryPath:targetFolder];
    [unzipTask setArguments:arguments];
    [unzipTask launch];
    [unzipTask waitUntilExit]; //remove this to start the task concurrently

}

That is a quick and dirty solution. In real life you will probably want to do more error checking and have a look at the unzip manpage for fancy arguments.