小编Poo*_*abu的帖子

我是Hadoop的新手.我想从mapper类的map函数中的main函数(Java程序)访问命令行参数.请建议如何做到这一点.

haduser@user-laptop:/usr/local/hadoop$ bin/hadoop dfs -copyFromLocal /tmp/input 
/user/haduser/input

11/12/14 14:21:00 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:54310. Already tried 0 time(s).

11/12/14 14:21:01 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:54310. Already tried 1 time(s).

11/12/14 14:21:02 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:54310. Already tried 2 time(s).

11/12/14 14:21:03 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:54310. Already tried 3 time(s).

11/12/14 14:21:04 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:54310. Already tried 4 time(s).

11/12/14 14:21:05 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:54310. …

我有以下代码

int i = 321;
char ch = i;
printf("%d", ch);

i在二进制是00000000 00000000 00000001 01000001和输出是65.从上面的代码中,我知道由于char只占用1个字节的内存,所以前3个字节i被删除,最后一个字节被分配给ch.因此结果.

我的机器是小端的.结果是ch基于底层机器的字节顺序吗？请澄清.

如何在不提示linux用户的情况下检测C中的键盘事件？也就是说,运行的程序应该通过按任意键终止.有人可以帮忙吗？