代码段

正则匹配字符串

+ (BOOL)invalidLog:(NSString *) textString{
    NSString* regex=@"";

    NSRange range = [textString rangeOfString:regex options:NSRegularExpressionSearch];
    BOOL invalid=range.location == NSNotFound;
    return invalid;
}

指定字符串拼接数组

NSString *regex=[keywords componentsJoinedByString:@"|"]

根据换行符获得NSString并转化为NSMutableArray

NSMutableArray *logStringArray=[[fileContents componentsSeparatedByCharactersInSet:[NSCharacterSet newlineCharacterSet]] mutableCopy];

获取文件创建年份

+ (NSInteger)yearWithFilePath:(NSString *)filePath{
    NSFileManager *fm =[NSFileManager defaultManager];
    NSDate *fileDate=[[fm attributesOfItemAtPath:filePath error:nil] objectForKey:NSFileCreationDate];
    NSCalendar *calendar = [NSCalendar currentCalendar];
    NSDateComponents *components = [calendar components:NSCalendarUnitYear|NSCalendarUnitMonth|NSCalendarUnitDay fromDate:fileDate];
    NSInteger year=[components year];
    return year;
}

去掉字符串前后空格

remain = [remain stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];

NSString转NSDate

NSString *format=@"yyyy MMM d HH:mm:ss";
NSString *localeIdentifier=@"en_US";

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:format];
[dateFormatter setLocale:[[NSLocale alloc]initWithLocaleIdentifier:localeIdentifier]]；

NSDate *date = [dateFormatter dateFromString:dateWithYear];

plist转NSDictionary

NSDictionary * dic=[[NSDictionary alloc] initWithContentsOfFile:path];

枚举文件夹

NSArray * dirArray = [fileManager contentsOfDirectoryAtPath:path error:nil];