File Management Class

OOFileManager.h

#import <Foundation/Foundation.h>

@interface OOFileManager : NSObject

+ (NSArray *)fileNames:(NSString *)fileName;
+ (BOOL)exists:(NSString *)fileName;
+ (BOOL)isDir:(NSString *)fileName;
+ (BOOL)resExists:(NSString *)fileName;
+ (void)makeDir:(NSString *)fileName;
+ (void)remove:(NSString *)fileName;
+ (BOOL)data2file:(NSData *)data fileName:(NSString *)fileName overwrite:(BOOL)overwrite;
+ (BOOL)data2file_add:(NSData *)data fileName:(NSString *)fileName;
+ (NSData *)file2data:(NSString *)fileName;
+ (NSData *)file2data:(NSString *)fileName offset:(unsigned long long)offset
							length:(unsigned long long)length;
+ (NSData *)res2data:(NSString *)res;
+ (NSData *)res2data:(NSString *)res offset:(unsigned long long)offset
						 length:(unsigned long long)length;
+ (BOOL)res2file:(NSString *)res fileName:(NSString *)fileName overwrite:(BOOL)overwrite;
+ (void)copyItem:(NSString *)fromPath toPath:(NSString *)toPath overwrite:(BOOL)overwrite;
+ (void)moveItem:(NSString *)fromPath toPath:(NSString *)toPath;
+ (NSString *)getDocPath:(NSString*)fileName;
+ (NSString *)getAppPath:(NSString *)fileName;

@end

OOFileManager.m

#import "OOFileManager.h"

@implementation OOFileManager

//ファイル一覧の取得
+ (NSArray*)fileNames:(NSString *)fileName
{
	if (![OOFileManager exists:fileName]) return Nil;
	NSString *path = [OOFileManager getDocPath:fileName];
	
	return [[NSFileManager defaultManager] contentsOfDirectoryAtPath:path error:nil];
}

//対象がディレクトリか
+ (BOOL)isDir:(NSString *)fileName
{
	BOOL isDir;
	NSString *path = [OOFileManager getDocPath:fileName];
	
	[[NSFileManager defaultManager] fileExistsAtPath:path isDirectory:&isDir];
	return isDir;
}

//ファイル・ディレクトリが存在するか
+ (BOOL)exists:(NSString *)fileName
{
	NSString *path = [OOFileManager getDocPath:fileName];
	
	return [[NSFileManager defaultManager] fileExistsAtPath:path];
}

//ファイル・ディレクトリが存在するか
+ (BOOL)resExists:(NSString *)fileName
{
	NSString *path = [OOFileManager getAppPath:fileName];
	
	return [[NSFileManager defaultManager] fileExistsAtPath:path];
}

//アプリ内のパスを得る
+ (NSString *)getAppPath:(NSString *)fileName
{
	NSString *path = [[NSBundle mainBundle] pathForResource:fileName ofType:@""];
	
	return path;
}

//プロジェクトフォルダのファイルのパス
+ (NSString *)getDocPath:(NSString *)fileName
{
	NSString *path = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"];
	path = [path stringByAppendingPathComponent:fileName];
	
	return path;
}

//ディレクトリの生成
+ (void)makeDir:(NSString *)fileName
{
	if ([OOFileManager exists:fileName]) return;
	NSString *path = [OOFileManager getDocPath:fileName];
	
	[[NSFileManager defaultManager] createDirectoryAtPath:path withIntermediateDirectories:YES attributes:nil error:nil];
}

//ファイル・ディレクトリの移動
+ (void)moveItem:(NSString *)fromPath toPath:(NSString *)toPath
{
	if (![OOFileManager exists:fromPath]) return;
	if ([OOFileManager exists:toPath]) return;
	
	NSString *pathFrom = [OOFileManager getDocPath:fromPath];
	NSString *pathTo = [OOFileManager getDocPath:toPath];
	
	[[NSFileManager defaultManager] moveItemAtPath:pathFrom toPath:pathTo error:nil];
}

//ファイル・ディレクトリのコピー
+ (void)copyItem:(NSString *)fromPath toPath:(NSString *)toPath overwrite:(BOOL)overwrite
{
	if (![OOFileManager exists:fromPath]) return;
	if ([OOFileManager exists:toPath]) {
		//上書き禁止の場合
		if (!overwrite) {
			return;
		}
	}
	
	NSString *pathFrom = [OOFileManager getDocPath:fromPath];
	NSString *pathTo = [OOFileManager getDocPath:toPath];
	NSError *err = [[NSError alloc] init];
	
	if (overwrite) {
		//旧ファイル・ディレクトリを削除
		[OOFileManager remove:toPath];
	}
	[[NSFileManager defaultManager] copyItemAtPath:pathFrom toPath:pathTo error:&err];
}

//ファイル・ディレクトリの削除
+ (void)remove:(NSString *)fileName
{
	if (![OOFileManager exists:fileName]) return;
	NSString *path = [OOFileManager getDocPath:fileName];
	
	[[NSFileManager defaultManager] removeItemAtPath:path error:nil];
}


//データ→ファイル
+ (BOOL)data2file:(NSData *)data fileName:(NSString *)fileName overwrite:(BOOL)overwrite
{
	if (data == Nil || data.length == 0) {
		return NO;
	}
	if ([OOFileManager exists:fileName]) {
		if (!overwrite) {
			return NO;
		}
	}
	NSString *path = [OOFileManager getDocPath:fileName];
	
	if (overwrite) {
		//旧ファイルを削除
		[OOFileManager remove:fileName];
	}
	return ([data writeToFile:path atomically:YES]);
}

//データ→ファイル(追加)
+ (BOOL)data2file_add:(NSData *)data fileName:(NSString *)fileName
{
	if (![OOFileManager exists:fileName]) {
		return NO;
	}
	NSString *path = [OOFileManager getDocPath:fileName];
	NSFileHandle *fh = [NSFileHandle fileHandleForWritingAtPath:path];
	if (fh) {
		@try {
			[fh seekToEndOfFile];
			[fh writeData:data];
			[fh closeFile];
			return YES;
		}
		@catch(id error) {
		}
	}
	return NO;
}

//ファイル→データ
+ (NSData *)file2data:(NSString *)fileName
{
	if (![OOFileManager exists:fileName]) {
		return Nil;
	}
	NSString *path = [OOFileManager getDocPath:fileName];
	
	return [[NSData alloc] initWithContentsOfFile:path];
}

//ファイル→データ(部分)
+ (NSData *)file2data:(NSString *)fileName offset:(unsigned long long)offset
							length:(unsigned long long)length
{
	if (![OOFileManager exists:fileName]) {
		return Nil;
	}
	NSString *path = [OOFileManager getDocPath:fileName];
	
	NSFileHandle *fh = [NSFileHandle fileHandleForReadingAtPath:path];
	NSData *data;
	if (fh) {
		@try {
			[fh seekToFileOffset:offset];
			data = [fh readDataOfLength:length];
			[fh closeFile];
			return data;
		} @catch (id error) {
		}
	}
	return nil;
}

//リソース→データ
+ (NSData *)res2data:(NSString *)res
{
	if (![OOFileManager resExists:res]) {
		return Nil;
	}
	NSString *path = [OOFileManager getAppPath:res];
	
	return [NSData dataWithContentsOfFile:path];
}

//リソース→データ(部分)
+ (NSData *)res2data:(NSString *)res offset:(unsigned long long)offset
						 length:(unsigned long long)length
{
	if (![OOFileManager resExists:res]) {
		return Nil;
	}
	NSString *path = [OOFileManager getAppPath:res];
	
	NSFileHandle *fh = [NSFileHandle fileHandleForReadingAtPath:path];
	NSData *data;
	if (fh) {
		@try {
			[fh seekToFileOffset:offset];
			data=[fh readDataOfLength:length];
			[fh closeFile];
			return data;
		} @catch (id error) {
		}
	}
	return nil;
}

//リソース→ファイル
+ (BOOL)res2file:(NSString *)res fileName:(NSString *)fileName overwrite:(BOOL)overwrite
{
	if (![OOFileManager resExists:res]) {
		return NO;
	}
	if ([OOFileManager exists:fileName]) {
		//上書き禁止の場合
		if (!overwrite) {
			return NO;
		}
	}
	NSString *from = [OOFileManager getAppPath:res];
	
	NSString *to = [OOFileManager getDocPath:fileName];
	
	if (overwrite) {
		//旧ファイル・ディレクトリを削除
		[OOFileManager remove:fileName];
	}
	[[NSFileManager defaultManager] copyItemAtPath:from toPath:to error:nil];
	
	return YES;
}

@end

Fork from above URL.
http://www.saturn.dti.ne.jp/npaka/iphone/util/index.html