//假設(shè)文件目錄下已經(jīng)存在fileA和fileB兩個文件
//把文件A的內(nèi)容添加到文件B的末尾
#import <Foundation/Foundation.h>
int main(int argc, const char * argv[]) {
    @autoreleasepool {
        // insert code here...
        NSFileHandle *originFile, *destinationFile;
        NSData *buffer;
        //打開文件進(jìn)行讀取操作
        originFile = [NSFileHandle fileHandleForReadingAtPath:@"fileA.txt"];
        //判斷文件是否打開讀取成功
        if (!originFile) {
            NSLog(@"Open of originFile for reading failed.");
            return 1;
        }else{
            NSLog(@"Open of originFile for reading successful.");
        }
        //打開要更新的文件
        destinationFile = [NSFileHandle fileHandleForWritingAtPath:@"FileB.txt"];
        //判斷文件打開寫入是否成功
        if (!destinationFile) {
            NSLog(@"Open of originFile for writing failed.");
            return 2;
        }else{
            NSLog(@"Open of destinationFile for writing successful.");
        }
        //在文件的末尾進(jìn)行查找
        [destinationFile seekToEndOfFile];
        //讀取寫入數(shù)據(jù)
        buffer = [originFile readDataToEndOfFile];
        [destinationFile writeData:buffer];
        //關(guān)閉文件
        [originFile closeFile];
        [destinationFile closeFile];
        //讀取打印文件內(nèi)容
        NSLog(@"%@",[NSString stringWithContentsOfFile:@"FileB.txt" encoding:NSUTF8StringEncoding error:NULL]);
    }
    return 0;
}