minimalpop minimalpop - 1 year ago 105
Objective-C Question

Iterating through files in a folder with nested folders - Cocoa

I need to access every file in a folder, including file that exist within nested folders. An example folder might look like this.


Say that I wanted to run a process on every file within "animals" that isn't folder. What would be the best way to iterate through the folder "animals" and all of its subfolders to access every file?


Answer Source

Use NSDirectoryEnumerator to recursively enumerate files and directories under the directory you want, and ask it to tell you whether it is a file or directory. The following is based on the example listed at the documentation for -[NSFileManager enumeratorAtURL:includingPropertiesForKeys:options:errorHandler:]:

NSFileManager *fileManager = [NSFileManager defaultManager];
NSURL *directoryURL = … // URL pointing to the directory you want to browse
NSArray *keys = [NSArray arrayWithObject:NSURLIsDirectoryKey];

NSDirectoryEnumerator *enumerator = [fileManager
    errorHandler:^(NSURL *url, NSError *error) {
        // Handle the error.
        // Return YES if the enumeration should continue after the error.
        return YES;

for (NSURL *url in enumerator) { 
    NSError *error;
    NSNumber *isDirectory = nil;
    if (! [url getResourceValue:&isDirectory forKey:NSURLIsDirectoryKey error:&error]) {
        // handle error
    else if (! [isDirectory boolValue]) {
        // No error and it’s not a directory; do something with the file