grep 练习题

1、找出/proc/meminfo文件中，所有以大写或小写S开头的行；至少有三种实现方式**

[root@HFJ audit]# grep -i ^s /proc/meminfo
SwapCached:            0 kB
SwapTotal:       1023992 kB
SwapFree:        1023992 kB
Shmem:               248 kB
Slab:             101952 kB
SReclaimable:      45604 kB
SUnreclaim:        56348 kB

[root@HFJ audit]# grep ^[Ss] /proc/meminfo 
SwapCached:            0 kB
SwapTotal:       1023992 kB
SwapFree:        1023992 kB
Shmem:               248 kB
Slab:             101956 kB
SReclaimable:      45604 kB
SUnreclaim:        56352 kB

[root@HFJ audit]# `egrep "^S|^s"  /proc/meminfo` 
SwapCached:            0 kB
SwapTotal:       1023992 kB
SwapFree:        1023992 kB
Shmem:               248 kB
Slab:             101956 kB
SReclaimable:      45604 kB
SUnreclaim:        56352 kB

[root@HFJ audit]# grep -v ^[^SS] /proc/meminfo
SwapCached:            0 kB
SwapTotal:       1023992 kB
SwapFree:        1023992 kB
Shmem:               248 kB
Slab:             101952 kB
SReclaimable:      45604 kB
SUnreclaim:        56348 kB

2、显示当前系统上root、centos或user1用户的相关信息；

[root@HFJ audit]# egrep "^root|^centos|^user1" /etc/passwd
root:x:0:0:tuser0,yizhuang 101 room,12312312,1111111:/root:/bin/bash
centos:x:4005:4005::/home/centos:/bin/bash
user1:x:4006:4006::/home/user1:/bin/bash

找出/etc/rc.d/init.d/functions文件中某单词后面跟一个小括号的行；

cat /etc/rc.d/init.d/functions |grep -w "[[:alpha:]]\+()"
checkpid() {
daemon() {
killproc() {
pidfileofproc() {
pidofproc() {
status() {
success() {
failure() {
passed() {
warning() {
action() {
strstr() {
confirm() {
[root@HFJ audit]# cat /etc/rc.d/init.d/functions |grep "\<[[:alpha:]]\+()"
checkpid() {
daemon() {
killproc() {
pidfileofproc() {
pidofproc() {
status() {
success() {
failure() {
passed() {
warning() {
action() {
strstr() {
confirm() {

[root@HFJ audit]# cat /etc/rc.d/init.d/functions |grep "\<[[:alpha:]]\+\>()"
checkpid() {
daemon() {
killproc() {
pidfileofproc() {
pidofproc() {
status() {
success() {
failure() {
passed() {
warning() {
action() {
strstr() {
confirm() {

3、使用echo命令输出一绝对路径，使用egrep取出基名；

[root@HFJ audit]# echo /etc/rc.d/init.d/functions |egrep [^/]+$
/etc/rc.d/init.d/functions
[root@HFJ audit]# echo /etc/rc.d/init.d/functions |egrep [^/]+[/]?$
/etc/rc.d/init.d/functions

5、找出ifconfig命令结果中的1-255之间的数值；

[root@HFJ audit]# ifconfig |egrep  "\<[[:digit:]]{1,2}\>|\<1[[:digit:]]{2}\>|\<2[0-4][0-9]\>|\<25[0-5]\>"
bond0     Link encap:Ethernet  HWaddr 00:0C:29:21:6F:D9  
          inet addr:192.168.1.100  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::20c:29ff:fe21:6fd9/64 Scope:Link
          UP BROADCAST RUNNING MASTER MULTICAST  MTU:1500  Metric:1
          RX packets:175980 errors:14 dropped:17 overruns:0 frame:0
          TX packets:22 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:15987550 (15.2 MiB)  TX bytes:1200 (1.1 KiB)
eth0      Link encap:Ethernet  HWaddr 00:0C:29:21:6F:BF  
          inet addr:192.168.3.250  Bcast:192.168.3.255  Mask:255.255.255.0
          inet6 addr: fe80::20c:29ff:fe21:6fbf/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:608281 errors:0 dropped:0 overruns:0 frame:0
          TX packets:431714 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:46518755 (44.3 MiB)  TX bytes:61328703 (58.4 MiB)
          Interrupt:19 Base address:0x2000 
eth1      Link encap:Ethernet  HWaddr 00:0C:29:21:6F:D9  
          UP BROADCAST RUNNING SLAVE MULTICAST  MTU:1500  Metric:1
          RX packets:169177 errors:0 dropped:0 overruns:0 frame:0
          TX packets:22 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:15508186 (14.7 MiB)  TX bytes:1200 (1.1 KiB)
          Interrupt:17 Base address:0x2400 
eth2      Link encap:Ethernet  HWaddr 00:0C:29:21:6F:D9  
          UP BROADCAST RUNNING SLAVE MULTICAST  MTU:1500  Metric:1
          RX packets:6803 errors:14 dropped:17 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:479364 (468.1 KiB)  TX bytes:0 (0.0 b)
          Interrupt:16 Base address:0x2080 

6、找出ifconfig命令结果中的IP地址；

[root@HFJ ~]# ifconfig |grep -w inet
          inet addr:192.168.1.100  Bcast:192.168.1.255  Mask:255.255.255.0
          inet addr:192.168.3.250  Bcast:192.168.3.255  Mask:255.255.255.0
          inet addr:192.168.70.253  Bcast:192.168.70.255  Mask:255.255.255.0
          inet addr:127.0.0.1  Mask:255.0.0.0
[root@HFJ ~]# ifconfig |grep -w inet|egrep -o "inet addr:[^[:space:]]+\>"
inet addr:192.168.1.100
inet addr:192.168.3.250
inet addr:192.168.70.253
inet addr:127.0.0.1
[root@HFJ ~]# ifconfig |grep -w inet|egrep -o "inet addr:[^[:space:]]+\>"|egrep "\<[0-9].*$"
inet addr:192.168.1.100
inet addr:192.168.3.250
inet addr:192.168.70.253
inet addr:127.0.0.1
[root@HFJ ~]# ifconfig |grep -w inet|egrep -o "inet addr:[^[:space:]]+\>"|egrep -o "\<[0-9].*$"
192.168.1.100
192.168.3.250
192.168.70.253
127.0.0.1

7、添加用户bash, testbash, basher以及nologin(其shell为/sbin/nologin)；而后找出/etc/passwd文件中用户名同shell名的行；

[root@HFJ ~]# egrep    "(^[^:]+\>)"  /etc/passwd
root:x:0:0:tuser0,yizhuang 101 room,12312312,1111111:/root:/bin/bash
bin:x:1:1:bin:/bin:/sbin/nologin
daemon:x:2:2:daemon:/sbin:/sbin/nologin
adm:x:3:4:adm:/var/adm:/sbin/nologin
lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
sync:x:5:0:sync:/sbin:/bin/sync
shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown

[root@HFJ ~]# egrep    "(^[^:]+\>).*\1$"  /etc/passwd
sync:x:5:0:sync:/sbin:/bin/sync
shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
halt:x:7:0:halt:/sbin:/sbin/halt
nologin:x:4010:4010::/home/nologin:/sbin/nologin