Linux命令

awk

打印第一行第二列

ps -ef | grep sshd | head -n1 | awk {'print $2'}
# example
[qingwyan@localhost smartphy114]$ ps -ef | grep sshd
root      1405     1  0 Nov23 ?        00:00:00 /usr/sbin/sshd -D
root     13092  1405  0 19:49 ?        00:00:00 sshd: qingwyan [priv]
qingwyan 13108 13092  0 19:49 ?        00:00:00 sshd: qingwyan@notty
qingwyan 16602 32280  0 21:07 pts/5    00:00:00 grep --color=auto sshd
root     20010  1405  0 Nov28 ?        00:00:02 sshd: root@pts/19

[qingwyan@localhost smartphy114]$ ps -ef | grep sshd | head -n1 | awk {'print $2'}
1405

sed

替換文本里所有符合條件字符

sed -i 's/原来字符/替换字符/g' "替换的文件名"