打印日志信息到文件

- (NSString*)logFilePath {
//非越狱版路径
#ifndef CRACK
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
//越狱版路径
#else
NSString *documentsDirectory = @"/var/root/Media/xiaodao/";
#endif
NSString *logDir = [documentsDirectory stringByAppendingPathComponent:@"logs"];
BOOL isDir = YES;
//如果logs文件夹存不存在，则创建
if([[NSFileManager defaultManager] fileExistsAtPath:logDir isDirectory:&isDir] == NO)
{
[[NSFileManager defaultManager] createDirectoryAtPath:logDir withIntermediateDirectories:YES attributes:nil error:nil];
}
//以当天的时间为文件名，文件名后缀为.log
NSString *fileName =[NSString stringWithFormat:@"%@.log",[NSDate date]];
NSString *logPath = [logDir stringByAppendingPathComponent:fileName];
return logPath;
}

1 - (void)startLog {
2    freopen([[self logFilePath] cStringUsingEncoding:NSASCIIStringEncoding],"a+",stderr);
3 }

1 - (void)finishLog {
2     fflush(stderr);
3     dup2(dup(STDERR_FILENO), STDERR_FILENO);
4     close(dup(STDERR_FILENO));
5 }

1 - (BOOL)deleteLogFile {
2     BOOL success = [[NSFileManager defaultManager] removeItemAtPath:[self logFilePath] error:nil];
3     return success;
4 }