NSFileManager contentsOfDirectoryAtPath example ios

contentsOfDirectoryAtPath :error:

Performs a shallow search of the specified directory and returns the paths of any contained items.

- (NSArray *)contentsOfDirectoryAtPath:(NSString *)path error:(NSError **)error

Parameters

path

The path to the directory whose contents you want to enumerate.

error

On input, a pointer to an error object. If an error occurs, this pointer is set to an actual error object containing the error information. You may specify nil for this parameter if you do not want the error information.

Return Value of [NSFileManager contentsOfDirectoryAtPath]

An array of NSString objects, each of which identifies a file, directory, or symbolic link contained in path. Returns an empty array if the directory exists but has no contents. If an error occurs, this method returnsnil and assigns an appropriate error object to the error parameter

Discussion of [NSFileManager contentsOfDirectoryAtPath]

This method performs a shallow search of the directory and therefore does not traverse symbolic links or return the contents of any subdirectories. This method also does not return URLs for the current directory (“.”), parent directory (“..”), or resource forks (files that begin with “._”) but it does return other hidden files (files that begin with a period character). If you need to perform a deep enumeration, use theenumeratorAtURL:includingPropertiesForKeys:options:errorHandler: method instead.

The order of the files in the returned array is undefined.

Example of [NSFileManager contentsOfDirectoryAtPath]

    NSArray *searchPaths = NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES);
    NSString* documentsPath = [searchPaths objectAtIndex: 0]; 

    NSError* error = nil;
    NSArray* filesArray = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:documentsPath error:&error];
    if(error != nil) {
        NSLog(@"Error in reading files: %@", [error localizedDescription]);
        return;
    }

    // sort by creation date
    NSMutableArray* filesAndProperties = [NSMutableArray arrayWithCapacity:[filesArray count]];
    for(NSString* file in filesArray) {
        NSString* filePath = [iMgr.documentsPath stringByAppendingPathComponent:file];
        NSDictionary* properties = [[NSFileManager defaultManager]
                                    attributesOfItemAtPath:filePath
                                    error:&error];
        NSDate* modDate = [properties objectForKey:NSFileModificationDate];

        if(error == nil)
        {
            [filesAndProperties addObject:[NSDictionary dictionaryWithObjectsAndKeys:
                                           file, @"path",
                                           modDate, @"lastModDate",
                                           nil]];                 
        }
    }

        // sort using a block
        // order inverted as we want latest date first
    NSArray* sortedFiles = [filesAndProperties sortedArrayUsingComparator:
                            ^(id path1, id path2)
                            {                               
                                // compare 
                                NSComparisonResult comp = [[path1 objectForKey:@"lastModDate"] compare:
                                                           [path2 objectForKey:@"lastModDate"]];
                                // invert ordering
                                if (comp == NSOrderedDescending) {
                                    comp = NSOrderedAscending;
                                }
                                else if(comp == NSOrderedAscending){
                                    comp = NSOrderedDescending;
                                }
                                return comp;                                
                            }];