Linux中的ps命令是Process Status的縮寫。ps命令用來列出系統(tǒng)中當(dāng)前運(yùn)行的那些進(jìn)程。ps命令列出的是當(dāng)前那些進(jìn)程的快照,就是執(zhí)行ps命令的那個(gè)時(shí)刻的那些進(jìn)程,如果想要?jiǎng)討B(tài)的顯示進(jìn)程信息,就可以使用top命令。
要對(duì)進(jìn)程進(jìn)行監(jiān)測(cè)和控制,首先必須要了解當(dāng)前進(jìn)程的情況,也就是需要查看當(dāng)前進(jìn)程,而 ps 命令就是最基本同時(shí)也是非常強(qiáng)大的進(jìn)程查看命令。使用該命令可以確定有哪些進(jìn)程正在運(yùn)行和運(yùn)行的狀態(tài)、進(jìn)程是否結(jié)束、進(jìn)程有沒有僵死、哪些進(jìn)程占用了過多的資源等等??傊蟛糠中畔⒍际强梢酝ㄟ^執(zhí)行該命令得到的。
ps 為我們提供了進(jìn)程的一次性的查看,它所提供的查看結(jié)果并不動(dòng)態(tài)連續(xù)的;如果想對(duì)進(jìn)程時(shí)間監(jiān)控,應(yīng)該用 :ref:top
工具。
注:kill 命令用于殺死進(jìn)程。
linux上進(jìn)程有5種狀態(tài):
ps工具標(biāo)識(shí)進(jìn)程的5種狀態(tài)碼:
[root@localhost test6]# ps -A
PID TTY TIME CMD
1 ? 00:00:00 init
2 ? 00:00:01 migration/0
3 ? 00:00:00 ksoftirqd/0
4 ? 00:00:01 migration/1
5 ? 00:00:00 ksoftirqd/1
6 ? 00:29:57 events/0
7 ? 00:00:00 events/1
8 ? 00:00:00 khelper
49 ? 00:00:00 kthread
54 ? 00:00:00 kblockd/0
55 ? 00:00:00 kblockd/1
56 ? 00:00:00 kacpid
217 ? 00:00:00 cqueue/0
……省略部分結(jié)果
[root@localhost test6]# ps -u root
PID TTY TIME CMD
1 ? 00:00:00 init
2 ? 00:00:01 migration/0
3 ? 00:00:00 ksoftirqd/0
4 ? 00:00:01 migration/1
5 ? 00:00:00 ksoftirqd/1
6 ? 00:29:57 events/0
7 ? 00:00:00 events/1
8 ? 00:00:00 khelper
49 ? 00:00:00 kthread
54 ? 00:00:00 kblockd/0
55 ? 00:00:00 kblockd/1
56 ? 00:00:00 kacpid
……省略部分結(jié)果
[root@localhost test6]# ps -ef
UID PID PPID C STIME TTY TIME CMD
root 1 0 0 Nov02 ? 00:00:00 init [3]
root 2 1 0 Nov02 ? 00:00:01 [migration/0]
root 3 1 0 Nov02 ? 00:00:00 [ksoftirqd/0]
root 4 1 0 Nov02 ? 00:00:01 [migration/1]
root 5 1 0 Nov02 ? 00:00:00 [ksoftirqd/1]
root 6 1 0 Nov02 ? 00:29:57 [events/0]
root 7 1 0 Nov02 ? 00:00:00 [events/1]
root 8 1 0 Nov02 ? 00:00:00 [khelper]
root 49 1 0 Nov02 ? 00:00:00 [kthread]
root 54 49 0 Nov02 ? 00:00:00 [kblockd/0]
root 55 49 0 Nov02 ? 00:00:00 [kblockd/1]
root 56 49 0 Nov02 ? 00:00:00 [kacpid]
[root@localhost test6]# ps -ef|grep ssh
root 2720 1 0 Nov02 ? 00:00:00 /usr/sbin/sshd
root 17394 2720 0 14:58 ? 00:00:00 sshd: root@pts/0
root 17465 17398 0 15:57 pts/0 00:00:00 grep ssh
[root@localhost test6]# ps -l
F S UID PID PPID C PRI NI ADDR SZ WCHAN TTY TIME CMD
4 S 0 17398 17394 0 75 0 - 16543 wait pts/0 00:00:00 bash
4 R 0 17469 17398 0 77 0 - 15877 - pts/0 00:00:00 ps
[root@localhost test6]# ps aux
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 1 0.0 0.0 10368 676 ? Ss Nov02 0:00 init [3]
root 2 0.0 0.0 0 0 ? S< Nov02 0:01 [migration/0]
root 3 0.0 0.0 0 0 ? SN Nov02 0:00 [ksoftirqd/0]
root 4 0.0 0.0 0 0 ? S< Nov02 0:01 [migration/1]
root 5 0.0 0.0 0 0 ? SN Nov02 0:00 [ksoftirqd/1]
root 6 0.0 0.0 0 0 ? S< Nov02 29:57 [events/0]
root 7 0.0 0.0 0 0 ? S< Nov02 0:00 [events/1]
root 8 0.0 0.0 0 0 ? S< Nov02 0:00 [khelper]
root 49 0.0 0.0 0 0 ? S< Nov02 0:00 [kthread]
root 54 0.0 0.0 0 0 ? S< Nov02 0:00 [kblockd/0]
root 55 0.0 0.0 0 0 ? S< Nov02 0:00 [kblockd/1]
root 56 0.0 0.0 0 0 ? S< Nov02 0:00 [kacpid]