c 字符串拼接更加方便

    int main(void)
    {
     char fullpath [100] = "/home/dimgtui"; //记录路径名
     printf("fullpath:%s\n",fullpath);

     char * ptr;//记录fullpath的最后位置，用于拼接
     ptr = fullpath + strlen(fullpath);
     *ptr ++ = '/';
     *ptr = 0;

     char * filename = "filename1";
     strcpy(ptr,filename);
     printf("fullpath:%s\n",fullpath);

     //恢复之前的fullpath
     ptr[-1] = 0;
     printf("fullpath:%s\n",fullpath);
     exit(0);
    }

    /*output
             fullpath :"/home/dimgtui"
             fullpath :"/home/dimgtui/filename1"
      fullpath :"/home/dimgtui"
    */