UIApplication+LoggerExtention.h

//
//
//  Created by nori on 2012/12/21.
//  Copyright (c) 2012年 nori. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface UIApplication(LoggerExtention)
+ (void)startLogging;
@end

@implementation UIApplication(LoggerExtention)
+ (void)startLogging
{
    // ファイルをsandboxのDocumentsに保存
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = paths[0];
    
    // ファイル名はタイム・スタンプを使う
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:@"yyyyMMddhhmmss"];
    [dateFormatter setTimeZone:[NSTimeZone systemTimeZone]];
    NSString *dateString = [dateFormatter stringFromDate:[NSDate date]];
    
    NSString *fileName = [NSString stringWithFormat:@"log%@", dateString];
    NSString *fileExtention = @"log";
    NSString *filePath = [[documentsDirectory stringByAppendingPathComponent:fileName]
                          stringByAppendingPathExtension:fileExtention];
    
    // ファイル名が重複している場合は、サフィックスをつける
    NSFileManager *fileManager = [NSFileManager defaultManager];
    if ([fileManager fileExistsAtPath:filePath]) {
        NSUInteger n = 2;
        do {
            filePath = [[documentsDirectory stringByAppendingPathComponent:[fileName stringByAppendingFormat:@"_%d",n]] stringByAppendingPathExtension:fileExtention];
            n++;
        }
        while ( [fileManager fileExistsAtPath:filePath] );
    }
    NSLog(@"%@", filePath);
    // ログをリダイレクト
    freopen([filePath cStringUsingEncoding:NSASCIIStringEncoding],"a+",stderr);
  NSLog(@"Start Logging");
	
    // バージョン情報をログに出力
	NSString *version = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleVersion"];
	NSLog(@"Bundle Version : %@",version);
}

@end