Regular expression job

1、 Show /etc/rc.d/rc.sysinit File with size insensitive h Beginning line ;

egrep "^[hH]" /etc/rc.d/rc.sysinit

2、 Show /etc/passwd China and Israel sh The line at the end ;

egrep "sh$" /etc/passwd

3、 Show /etc/fstab China and Israel # start , One or more whitespace characters followed by , And then it's followed by any non whitespace line ;

egrep "^#[[:space:]]*[^[:space:]]\{1,\}" /etc/fstab

4、 lookup /etc/rc.d/rc.local Contained in the “ With to Start with to ending ” Word serial of ;

egrep -w "^to[a-Z]*to$" /etc/rc.d/rc.local

5、 lookup /etc/inittab contains “ With s start , And d Ending words ” Pattern line ;

egrep -w "^s[a-Z]*d$"  /etc/inittab

6、 lookup ifconfig In the command result 1-255 Integer between ;

ifconfig | egrep -w "[1-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5]"

7、 Show /var/log/secure The file contains “Failed” or “FAILED” The line of ;

egrep -w "Failed|FAILED" /var/log/secure

8、 stay /etc/passwd Take out the default shell by bash The line of ;

egrep -w "bash" /etc/shells

9、 List... In long format /etc/ Directory to ns start 、.conf File information at the end ;

10、 Highlight passwd Colon in file , And the characters on both sides

egrep "[a-Z][1-9]*:[1-9][a-Z]*" /etc/passwd