CODEWITHSUNDEEP
iphoneiosobjective-cdirectorynsfilemanager
Chris Loonam
Chris Loonam

Reputation: 5745

iOS Read multiple subdirectories

I'm trying to read directories, and then get the path for the files in those directories. The problem is, I don't know how many subdirectories there may be in a folder, and this code

NSString *path;
if ([[NSFileManager defaultManager] fileExistsAtPath:[[self downloadsDir] stringByAppendingPathComponent:[tableView cellForRowAtIndexPath:indexPath].textLabel.text]]) {
    path = [[self downloadsDir] stringByAppendingPathComponent:[NSString stringWithFormat:@"%@", [tableView cellForRowAtIndexPath:indexPath].textLabel.text]];
}
else{
    for (NSString *subdirs in [[NSFileManager defaultManager] contentsOfDirectoryAtPath:[self downloadsDir] error:nil]) {
        BOOL dir;
        [[NSFileManager defaultManager] fileExistsAtPath:[[self downloadsDir] stringByAppendingPathComponent:subdirs] isDirectory:&dir];
        if (dir) {
            for (NSString *f in [[NSFileManager defaultManager] contentsOfDirectoryAtPath:[[self downloadsDir] stringByAppendingPathComponent:subdirs] error:nil]) {
                if ([f isEqualToString:[tableView cellForRowAtIndexPath:indexPath].textLabel.text]) {
                    path = [[self downloadsDir] stringByAppendingPathComponent:[NSString stringWithFormat:@"%@/%@", subdirs, f]];
                }
            }
        }
    }
}

only reads up to one subdirectory, and gives me the path for the file im looking for. I cant find a way better than this to get multiple subdirectories and the paths of the files in those directories. Can anyone help with this? Heres what im trying to do

+Downloads Folder+
    +File1+ //I can get the path for this
    +Directory1+ 
         +Directory2+ 
             +File3+ // I want to get the path for this, but don't know how
         +File2+ // I can get the path for this

I feel like if I just keep repeating the for loop that gets the contents of the directory I might have a problem eventually.

Upvotes: 0

Views: 115

Answers (1)

Fran Sevillano
Fran Sevillano

Reputation: 8163

There is a concept called recursion, that is commonly applied to problems like this one. Basically, you call that very method for each of the sub-directories, which in turn, will call it for each of the sub-sub-directories, and so on.

The important thing is that you define a stop point, so it doesn't go on forever. Seems like a good stop point would be a file or an empty directory.

In pseudo-code:

method storePaths(directory)
    for each element in  directory
        if element is a file
            store path
        else if element not empty directory
             call storePaths(element)

Upvotes: 1

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