Rocky基础练习题---grep练习题

1、显示/proc/meminfo文件中以大小s开头的行(要求：使用两种方法)

[root@rocky8 ~]# cat /proc/meminfo |egrep -io '^[s].*'
SwapCached:            0 kB
SwapTotal:       4194300 kB
SwapFree:        4194300 kB
Shmem:              8860 kB
Slab:              95680 kB
SReclaimable:      44736 kB
SUnreclaim:        50944 kB
ShmemHugePages:        0 kB
ShmemPmdMapped:        0 kB
[root@rocky8 ~]# cat /proc/meminfo |egrep -v '^[^s|S].*'
SwapCached:            0 kB
SwapTotal:       4194300 kB
SwapFree:        4194300 kB
Shmem:              8860 kB
Slab:              95676 kB
SReclaimable:      44736 kB
SUnreclaim:        50940 kB
ShmemHugePages:        0 kB
ShmemPmdMapped:        0 kB
[root@rocky8 ~]# cat /proc/meminfo |egrep -o '^[sS].*'
SwapCached:            0 kB
SwapTotal:       4194300 kB
SwapFree:        4194300 kB
Shmem:              8860 kB
Slab:              95676 kB
SReclaimable:      44736 kB
SUnreclaim:        50940 kB
ShmemHugePages:        0 kB
ShmemPmdMapped:        0 kB
[root@rocky8 ~]# egrep -io  '^[s].*' /proc/meminfo 
SwapCached:            0 kB
SwapTotal:       4194300 kB
SwapFree:        4194300 kB
Shmem:              8860 kB
Slab:              95680 kB
SReclaimable:      44736 kB
SUnreclaim:        50944 kB
ShmemHugePages:        0 kB
ShmemPmdMapped:        0 kB
[root@rocky8 ~]# cat /proc/meminfo |sed -rn '/^[sS].*/p'
SwapCached:            0 kB
SwapTotal:       4194300 kB
SwapFree:        4194300 kB
Shmem:              8860 kB
Slab:              95684 kB
SReclaimable:      44736 kB
SUnreclaim:        50948 kB
ShmemHugePages:        0 kB
ShmemPmdMapped:        0 kB

2、显示/etc/passwd文件中不以/bin/bash结尾的行

[root@rocky8 ~]# cat /etc/passwd |egrep  -v '/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
halt:x:7:0:halt:/sbin:/sbin/halt
mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
....

3、显示用户rpc默认的shell程序

[root@rocky8-1 ~]#cat /etc/passwd |egrep '^rpc:'|cut -d: -f7
/sbin/nologin
[root@rocky8 ~]# cat /etc/passwd |egrep adm|egrep -o '[^0-9:]+$'
/sbin/nologin

4、找出/etc/passwd中的两位或三位数

[root@rocky8 ~]# cat /etc/passwd |egrep -o '<[0-9]{2,3}>'

5、显示CentOS7的/etc/grub2.cfg文件中，至少以一个空白字符开头的且后面有非空白字符的行

[root@rocky8 ~]# cat /etc/grub2.cfg |egrep '^[[:space:]]+[^[:space:]]+'

6、找出“netstat -tan”命令结果中以LISTEN后跟任意多个空白字符结尾的行

[root@rocky8 ~]# netstat -tan |egrep 'LISTEN[[:space:]]+$'
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN     
tcp6       0      0 :::22                   :::*                    LISTEN

7、显示CentOS7上所有UID小于1000以内的用户名和UID

[root@rocky8 ~]# cat /etc/passwd |egrep '<x:[0-9]{1,3}>' |cut -d: -f1,3
root:0
bin:1
daemon:2
adm:3
lp:4
sync:5
shutdown:6
halt:7
mail:8
...

8、添加用户bash、testbash、basher、sh、nologin(其shell为/sbin/nologin),找出/etc/passwd用户名和shell同名的行

[root@rocky8 ~]# for i in bash testbash basher sh nologin;do useradd -s /sbin/nologin $i;done
[root@rocky8 ~]# tail -5 /etc/passwd
bash:x:1001:1001::/home/bash:/sbin/nologin
testbash:x:1002:1002::/home/testbash:/sbin/nologin
basher:x:1003:1003::/home/basher:/sbin/nologin
sh:x:1004:1004::/home/sh:/sbin/nologin
nologin:x:1005:1005::/home/nologin:/sbin/nologin
[root@rocky8 ~]# cat /etc/passwd |egrep '^(.*>).*<1$'
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:1005:1005::/home/nologin:/sbin/nologin

9、利用df和grep，取出磁盘各分区利用率，并从大到小排序

[root@rocky8 ~]# df |egrep '/dev/sda'|egrep -o '[0-9]{1,3}%'|sort -rn
20%
7%

10、显示三个用户root、mage、wang的UID和默认shell

[root@rocky8 ~]# cat /etc/passwd | egrep   '^(root|mage|wang)>'|cut -d: -f3,7
0:/bin/bash

11、找出/etc/rc.d/init.d/functions文件中行首为某单词(包括下划线)后面跟一个小括号的行

[root@rocky8 ~]# cat /etc/init.d/functions |egrep '^<[a-Z_]+>()'
checkpid() {
__kill_pids_term_kill_checkpids() {
__kill_pids_term_kill() {
__pids_var_run() {
__pids_pidof() {
daemon() {
killproc() {
pidfileofproc() {
pidofproc() {
status() {
echo_success() {
echo_failure() {
echo_passed() {
echo_warning() {
update_boot_stage() {
success() {
failure() {
passed() {
warning() {
action() {
strstr() {
is_ignored_file() {
is_true() {
is_false() {
apply_sysctl() {

12、使用egrep取出/etc/rc.d/init.d/functions中其基名

[root@rocky8 ~]# echo /etc/rc.d/init.d/functions | egrep -o '[^/]+/?$'
functions

13、使用egrep取出上面路径的目录名

[root@rocky8 ~]# echo /etc/rc.d/init.d/functions | egrep -o '.*/' |egrep -o '.*[^/]'
/etc/rc.d/init.d

14、统计last命令中以root登录的每个主机IP地址登录次数

[root@rocky8-1 ~]#last|egrep 'root'|egrep -o '([0-9]{1,3}.){3}[0-9]{1,3}'|sort|uniq -c
     42 10.0.0.1

15、利用扩展正则表达式分别表示0-9、10-99、100-199、200-249、250-255

[root@rocky8 ~]# seq 255 |egrep -o "<[0-9]>"
1
2
3
4
5
6
7
8
9
[root@rocky8 ~]# seq 255 |egrep -o "<[0-9]{2}>"
10
11
12
13
...
[root@rocky8 ~]# seq 255 |egrep -o "<[1][0-9]{2}>"
100
101
102
...
[root@rocky8 ~]# seq 255 |egrep -o "<[2][0-4][0-9]>"
200
201
202
203
204
205
...

[root@rocky8 ~]# seq 255 |egrep -o "<[2][5][0-5]>"
250
251
252
253
254
255

16、显示ifconfifig命令结果中所有IPv4地址

[root@rocky8 ~]# ifconfig|egrep -o '([0-9]{1,3}.){3}[0-9]{1,3}'|egrep -v -e '^255' -e'255$'
10.0.0.151
127.0.0.1
[root@rocky8 ~]# ifconfig|egrep -o '([0-9]{1,3}.){3}[0-9]{1,3}'|egrep -v '^255|255$'
10.0.0.151
127.0.0.1

17、将此字符串：welcome to magedu linux 中的每个字符去重并排序，重复次数多的排到前面

[root@rocky8 ~]# echo welcome to magedu linux|egrep -o "[^ ]" |sort|uniq -c|sort -rn
      3 e
      2 u
      2 o
      2 m
      2 l
      1 x
      1 w
      1 t
      1 n
      1 i
      1 g
      1 d
      1 c
      1 a

18、找出ifconfifig “网卡名” 命令结果中本机的IPv4地址

[root@rocky8 ~]# ifconfig ens160 |egrep -o '([0-9]{1,3}.){3}[0-9]{1,3}'|egrep -v "^255|255$"
10.0.0.151

19、查出分区空间使用率的最大百分比值

[root@rocky8 ~]# df|egrep "/dev/sd"|egrep -o "[0-9]{1,3}%"|sort -rn|head -1
20%

20、查出用户UID最大值的用户名、UID及shell类型

[root@rocky8 ~]# cat /etc/passwd |cut -d: -f1,3,7|sort -rn -t: -k2|head -1
nobody:65534:/sbin/nologin

21、查出/tmp的权限，以数字方式显示

[root@rocky8 ~]# stat /tmp |egrep Uid|cut -d/ -f1|cut -d( -f2
1777
[root@rocky8 ~]# stat /tmp|egrep Uid|cut -d/ -f1|tr -dc '[0-9
]+'
1777

22、统计当前连接本机的每个远程主机IP的连接数，并按从大到小排序

[root@rocky8 ~]# ss -nt  |egrep '^ESTAB' |tr -s ' ' : |cut -d: -f6|sort |uniq -c|sort -rn
      2 10.0.0.1