1.grep -Ew “^(root|mage|wang)” /etc/passwd |cut -d: -f3,7

2.cat /etc/rc.d/init.d/functions | grep -E “^a-z_.(.)”

3.echo /etc/rc.d/init.d/functions | grep -Eo “^/*/?$”

4.echo /etc/rc.d/init.d/functions | grep -Eo “^/.*/”

echo /etc/rc.d/init.d/functions | grep -Eo “.*\<”

5.last | grep “^root” | tr -s ” ” | cut -d” ” -f3 | grep -E “^(0-9{1,3}.){3}(0-9{1,3}){1}” | uniq -c

6.

1.0-9 ：0-9

2.10-99 ： grep -Ewo “1-9” /etc/passwd

3.100-199: grep -Ewo “10-9” /etc/passwd

4.200-249:grep -Ewo “20-4” /etc/passwd

5.250-255:grep -Ewo “250-5” /etc/passwd

7.

ifconfig |grep -E “(0-9{1,3}.){3}(0-9{1,3}){1}”

8.