一、什么是pidof命令？
复制代码 代码如下:#man pidof中的解释：
pidof — find the process ID of a running program.
pidof–用于查找一个运行的程序的PID。
pidof is actually the same program as killall5;
[root@GoGo ~]# ls -l /sbin/pidof
lrwxrwxrwx. 1 root root 8 Aug 25 00:40 /sbin/pidof -> killall5 //的确如此。
二、pidof命令的参数
-s 表示只返回1个 pid
-x 表示同时返回运行给定程序的 shell 的 pid
-o 表示告诉 piod 表示忽略后面给定的 pid ，可以使用多个 -o 。
pidof is simply a (symbolic) link to the killall5 program, which should also be located in /sbin.
When pidof is invoked with a full pathname to the program it should find the pid of, it is reasonably safe. Otherwise it
is possible that it returns pids of running programs that happen to have the same name as the program you're after but are
actually other programs.
如果 是一个 fullpath 则 pidof 不会出错，但如果不是则有可能返回和给定同名的程序。

三、pidof命令使用实例
复制代码 代码如下:[root@GoGo ~]# pidof nginx
1476 1475 1473 1472 1471 1470 1469 1467 1466
[root@GoGo ~]# ps -ef | grep nginx
nginx     1450  1449  0 20:16 ?        00:00:00 php-fpm: pool www
nginx     1451  1449  0 20:16 ?        00:00:00 php-fpm: pool www
nginx     1452  1449  0 20:16 ?        00:00:00 php-fpm: pool www
nginx     1453  1449  0 20:16 ?        00:00:00 php-fpm: pool www
nginx     1454  1449  0 20:16 ?        00:00:00 php-fpm: pool www
root      1466     1  0 20:16 ?        00:00:00 nginx: master process /usr/sbin/nginx -c /etc/nginx/nginx.conf
nginx     1467  1466  0 20:16 ?        00:00:00 nginx: worker process
nginx     1469  1466  0 20:16 ?        00:00:00 nginx: worker process
nginx     1470  1466  0 20:16 ?        00:00:00 nginx: worker process
nginx     1471  1466  0 20:16 ?        00:00:00 nginx: worker process
nginx     1472  1466  0 20:16 ?        00:00:00 nginx: worker process
nginx     1473  1466  0 20:16 ?        00:00:00 nginx: worker process
nginx     1475  1466  0 20:16 ?        00:00:00 nginx: worker process
nginx     1476  1466  0 20:16 ?        00:00:00 nginx: worker process
root      2234  2141  0 20:24 pts/1    00:00:00 grep nginx
[root@GoGo ~]# ps -ef | grep nginx | awk '{print $2}'
1450
1451
1452
1453
1454
1466
1467
1469
1470
1471
1472
1473
1475
1476
2237
[root@GoGo ~]# pidof -s nginx
1476
[root@GoGo ~]# pidof sshd
2139 1163
[root@GoGo ~]# ps -ef | grep sshd
root      1163     1  0 20:16 ?        00:00:00 /usr/sbin/sshd
root      2139  1163  0 20:20 ?        00:00:00 sshd: root@pts/1