Question

I am trying to use objective zip (v1.01e) in an IOS4 application as I want the ability to send password protected zip files via email.

I have got the objective zip source code files in my application, but am experiencing some problems following this getting started guide. http://code.google.com/p/objective-zip/wiki/GettingStarted

I use the following command

ZipFile *zipFile= [[ZipFile alloc] initWithFileName:@"yourFiles.zip" mode:ZipFileModeCreate];

But this always fails returning null via the code shown below from method zipOpen2 (line 507). Here:

if (ziinit.filestream == NULL)
        return NULL;

Following the stack trace it passes though the following methods:

//First
- (id) initWithFileName:(NSString *)fileName mode:(ZipFileMode)mode 

//Second
extern zipFile ZEXPORT zipOpen (pathname, append)

//Third
extern zipFile ZEXPORT zipOpen2 (pathname, append, globalcomment, pzlib_filefunc_def)

However, I notice the second method has this code.

extern zipFile ZEXPORT zipOpen (pathname, append)
    const char *pathname;
    int append;
{
    return zipOpen2(pathname,append,NULL,NULL);
}

When I query the value of the string pathname (in GDB) from this method on I get:

0x1b7f30 does not appear to point to a valid object.

So my questions:

1. What is const char *pathname, what does it do and is it messing up the pathname? AFAIK char is a single character which cant possibly represent a file name??
2. The code shown comes from source code of the objective zip project and not my own so I assume its working. It may be my misunderstanding of it. So what other possible reasons could be causing this problem?

For some more info initWithFileName: takes the parameter, filename and passes it on to zipOpen() by creating a pointer to file name as follows.

_fileName = [fileName retain];

Answer 1

Eventually I managed to solve this problem. The issue was because I was not appending the application’s documents directory location to the beginning of the file name.

Once I did this all was well.