Linux 文本处理工具练习

mac2024-12-01  22

一、找出ifconfig “网卡名” 命令结果中本机的IPv4地址

ifconfig eth0 | head -n 2 | tail -n 1 | tr -s ' ' : | cut -d : -f 4

[root@centos6 ~]#ifconfig eth0 | head -n 2 | tail -n 1 | tr -s ' ' : | cut -d : -f 4 192.168.30.133

 

 

二、查出分区空间使用率的最大百分比值

df | tr -s ' ' % | cut -d % -f 5 | sort -nr | head -n 1

[root@centos6 ~]#df | tr -s ' ' % | cut -d % -f 5 | sort -nr | head -n 1 100

 

 

三、查出用户UID最大值的用户名、 UID及shell类型

getent passwd | cut -d : -f 1,3,7 | sort -t : -k 2 -nr | head -n 1

[root@centos6 ~]#getent passwd | cut -d : -f 1,3,7 | sort -t : -k 2 -nr | head -n 1 nfsnobody:65534:/sbin/nologin

 

 

四、查出/tmp的权限,以数字方式显示

方法1:

stat /tmp/ | head -n 4 | tail -n 1 | tr -s ' ' : | cut -d : -f 2 | cut -b 2-5

[root@centos6 ~]#stat /tmp/ | head -n 4 | tail -n 1 | tr -s ' ' : | cut -d : -f 2 | cut -b 2-5 1777

 

方法2:

stat /tmp/ | head -n 4 | tail -n 1 | cut -d / -f 1 | cut -d '(' -f 2

[root@centos6 ~]#stat /tmp/ | head -n 4 | tail -n 1 | cut -d / -f 1 | cut -d '(' -f 2 1777

 

方法3

stat -c %a /tmp/

[root@centos6 ~]#stat -c %a /tmp/ 1777

 

 

五、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

cat /data/access_log | cut -d ' ' -f 1 | sort | uniq -c | sort -t ' ' -k 2 -nr

[root@centos6 ~]#cat /data/access_log | cut -d ' ' -f 1 | sort | uniq -c | sort -t ' ' -k 2 -nr 159091 172.18.56.3 4004 192.168.27.6 24 172.18.0.100

 

 

 

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

方法一:

cat /proc/meminfo | grep -o "^[Ss].*"

[root@centos7 ~]#cat /proc/meminfo | grep -o "^[Ss].*" SwapCached: 1616 kB SwapTotal: 2097148 kB SwapFree: 2088468 kB Shmem: 5420 kB Slab: 86776 kB SReclaimable: 32832 kB SUnreclaim: 53944 kB

 

方法二:

cat /proc/meminfo | grep -o "\<[Ss].*"

[root@centos7 ~]#cat /proc/meminfo | grep -o "\<[Ss].*" SwapCached: 1632 kB SwapTotal: 2097148 kB SwapFree: 2088484 kB Shmem: 5436 kB Slab: 86824 kB SReclaimable: 32832 kB SUnreclaim: 53992 kB

 

 

七、显示/etc/passwd文件中不以/bin/bash结尾的行

getent passwd | grep -v "/bin/bash$"

[root@centos7 ~]#getent passwd | grep -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 operator:x:11:0:operator:/root:/sbin/nologin games:x:12:100:games:/usr/games:/sbin/nologin ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin nobody:x:99:99:Nobody:/:/sbin/nologin systemd-network:x:192:192:systemd Network Management:/:/sbin/nologin dbus:x:81:81:System message bus:/:/sbin/nologin polkitd:x:999:998:User for polkitd:/:/sbin/nologin abrt:x:173:173::/etc/abrt:/sbin/nologin libstoragemgmt:x:998:997:daemon account for libstoragemgmt:/var/run/lsm:/sbin/nologin rpc:x:32:32:Rpcbind Daemon:/var/lib/rpcbind:/sbin/nologin colord:x:997:996:User for colord:/var/lib/colord:/sbin/nologin saslauth:x:996:76:Saslauthd user:/run/saslauthd:/sbin/nologin rtkit:x:172:172:RealtimeKit:/proc:/sbin/nologin chrony:x:995:993::/var/lib/chrony:/sbin/nologin qemu:x:107:107:qemu user:/:/sbin/nologin tss:x:59:59:Account used by the trousers package to sandbox the tcsd daemon:/dev/null:/sbin/nologin usbmuxd:x:113:113:usbmuxd user:/:/sbin/nologin geoclue:x:994:991:User for geoclue:/var/lib/geoclue:/sbin/nologin rpcuser:x:29:29:RPC Service User:/var/lib/nfs:/sbin/nologin nfsnobody:x:65534:65534:Anonymous NFS User:/var/lib/nfs:/sbin/nologin radvd:x:75:75:radvd user:/:/sbin/nologin setroubleshoot:x:993:990::/var/lib/setroubleshoot:/sbin/nologin pulse:x:171:171:PulseAudio System Daemon:/var/run/pulse:/sbin/nologin gdm:x:42:42::/var/lib/gdm:/sbin/nologin gnome-initial-setup:x:992:987::/run/gnome-initial-setup/:/sbin/nologin sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin avahi:x:70:70:Avahi mDNS/DNS-SD Stack:/var/run/avahi-daemon:/sbin/nologin postfix:x:89:89::/var/spool/postfix:/sbin/nologin ntp:x:38:38::/etc/ntp:/sbin/nologin tcpdump:x:72:72::/:/sbin/nologin gentoo:x:1002:1002:Gentoo Distribution:/home/gentoo:/bin/csh sarah:x:1005:1006::/home/sarah:/sbin/nologin

 

 

八、显示用户rpc默认的shell程序

getent passwd | grep "\<rpc\>" | cut -d : -f 7

[root@centos7 ~]#getent passwd | grep "\<rpc\>" | cut -d : -f 7 /sbin/nologin

 

 

九、找出/etc/passwd中的两位或三位数

方法一:

getent passwd | grep -Ewo "[[:digit:]]{2,3}"

[root@centos7 ~]#getent passwd | grep -Ewo "[[:digit:]]{2,3}" 12 11 12 100 14 50 99 99 192 192 81 81 999 998 173 173 998 997 32 32 997 996 996 76 172 172 995 993 107 107 59 59 113 113 994 991 29 29 75 75 993 990 171 171 42 42 992 987 74 74 70 70 89 89 38 38 72 72

 

方法二:

getent passwd | grep -Eo "\<[[:digit:]]{2,3}\>"

[root@centos7 ~]#getent passwd | grep -Eo "\<[[:digit:]]{2,3}\>" 12 11 12 100 14 50 99 99 192 192 81 81 999 998 173 173 998 997 32 32 997 996 996 76 172 172 995 993 107 107 59 59 113 113 994 991 29 29 75 75 993 990 171 171 42 42 992 987 74 74 70 70 89 89 38 38 72 72

 

 

十、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存非空白字符的行

cat /etc/grub2.cfg | grep -o "^ .*"

[root@centos7 ~]#cat /etc/grub2.cfg | grep -o "^ .*" load_env set default="${next_entry}" set next_entry= save_env next_entry set boot_once=true set default="${saved_entry}" menuentry_id_option="--id" menuentry_id_option="" set saved_entry="${prev_saved_entry}" save_env saved_entry set prev_saved_entry= save_env prev_saved_entry set boot_once=true if [ -z "${boot_once}" ]; then saved_entry="${chosen}" save_env saved_entry fi if [ x$feature_all_video_module = xy ]; then insmod all_video else insmod efi_gop insmod efi_uga insmod ieee1275_fb insmod vbe insmod vga insmod video_bochs insmod video_cirrus fi set timeout_style=menu set timeout=5 set timeout=5 source ${prefix}/user.cfg if [ -n "${GRUB2_PASSWORD}" ]; then set superusers="root" export superusers password_pbkdf2 root ${GRUB2_PASSWORD} fi source ${config_directory}/custom.cfg source $prefix/custom.cfg;

 

 

十一、找出“netstat -tan”命令的结果中以‘LISTEN’后跟任意多个空白字符结尾的行

netstat -tan | grep "LISTEN[[:space:]]\+$"

[root@centos7 ~]#netstat -tan | grep "LISTEN[[:space:]]\+$" tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN tcp 0 0 192.168.122.1:53 0.0.0.0:* LISTEN tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN tcp 0 0 127.0.0.1:631 0.0.0.0:* LISTEN tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN tcp 0 0 127.0.0.1:6010 0.0.0.0:* LISTEN tcp6 0 0 :::111 :::* LISTEN tcp6 0 0 :::22 :::* LISTEN tcp6 0 0 ::1:631 :::* LISTEN tcp6 0 0 ::1:25 :::* LISTEN tcp6 0 0 ::1:6010 :::* LISTEN

 

 

十二、显示CentOS7上所有系统用户的用户名和UID

getent passwd | grep "/sbin/nologin$" | cut -d : -f 1,3

[root@centos7 ~]#getent passwd | grep "/sbin/nologin$" | cut -d : -f 1,3 bin:1 daemon:2 adm:3 lp:4 mail:8 operator:11 games:12 ftp:14 nobody:99 systemd-network:192 dbus:81 polkitd:999 abrt:173 libstoragemgmt:998 rpc:32 colord:997 saslauth:996 rtkit:172 chrony:995 qemu:107 tss:59 usbmuxd:113 geoclue:994 rpcuser:29 nfsnobody:65534 radvd:75 setroubleshoot:993 pulse:171 gdm:42 gnome-initial-setup:992 sshd:74 avahi:70 postfix:89 ntp:38 tcpdump:72 sarah:1005

 

 

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

1. 添加用户

useradd

[root@centos7 ~]#useradd bash [root@centos7 ~]#useradd testbash [root@centos7 ~]#useradd basher [root@centos7 ~]#useradd sh [root@centos7 ~]#useradd -s /sbin/nologin nologin

2. 找出/etc/passwd用户名同shell名的行

getent passwd | grep "^\(\<.*\>\).*\1$"

[root@centos7 ~]#getent passwd | grep "^\(\<.*\>\).*\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 bash:x:1009:1014::/home/bash:/bin/bash sh:x:1012:1017::/home/sh:/bin/bash nologin:x:1013:1018::/home/nologin:/sbin/nologin

 

 

十四、利用df和grep,取出磁盘各分区利用率,并从大到小排序

df | grep "/dev/sd" | grep -o "[[:digit:]]\{1,3\}%" | grep -o "[[:digit:]]\+" | sort -nr

[root@centos7 ~]#df | grep "/dev/sd" | grep -o "[[:digit:]]\{1,3\}%" | grep -o "[[:digit:]]\+" | sort -nr 16 9 1

 

 

十五、显示三个用户root、 mage、 wang的UID和默认shell

方法一:

getent passwd | grep -E "^\<(root|mage|wang)\>" | cut -d : -f 1,3,7  

[root@centos7 ~]#getent passwd | grep -E "^\<(root|mage|wang)\>" | cut -d : -f 1,3,7 root:0:/bin/bash mage:1014:/bin/bash wang:1015:/bin/bash

 

方法二:

getent passwd | grep -Ew "^(root|mage|wang)" | cut -d : -f 1,3,7

[root@centos7 ~]#getent passwd | grep -Ew "^(root|mage|wang)" | cut -d : -f 1,3,7 root:0:/bin/bash mage:1014:/bin/bash wang:1015:/bin/bash

 

 

十六、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

cat /etc/rc.d/init.d/functions | grep -Eo "^.*\>\(\)"

[root@centos7 ~]#cat /etc/rc.d/init.d/functions | grep -Eo "^.*\>\(\)" 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()

 

 

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

echo /etc/rc.d/init.d/functions | grep -Eo "[^/]*/?$"

思路:

从行尾开始匹配任意字符,遇到/结束。由于基名可以是文件或目录,所以在$前加上/?匹配0或1次/。

[root@centos7 ~]#echo /etc/rc.d/init.d/functions | grep -Eo "[^/]*/?$" functions

 

 

十八、使用egrep取出上面路径的目录名

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

思路:

从行首开始匹配任意字符,遇到词首结束。由于正则表达式默认为贪婪模式,会匹配到最后一个单词的词首。

[root@centos7 ~]#echo /etc/rc.d/init.d/functions | grep -Eo ".*\<" /etc/rc.d/init.d/

 

 

十九、统计last命令中以root登录的每个主机IP地址登录次数

方法一:

last | grep "^\<root\>" | grep -Eo "\<([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>" | sort | uniq -c

[root@centos7 ~]#last | grep "^\<root\>" | grep -Eo "\<([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>" | sort | uniq -c 1 127.0.0.1 1 192.168.1.102 1 192.168.1.103 1 192.168.1.108 1 192.168.1.110 37 192.168.30.1 1 192.168.30.133 1 192.168.30.139

 

方法二:

思路:

由于IP地址格式为X.X.X.X,前三处格式都为X.,可以使用{3}归纳。

last | grep -Eo "\<(([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>" | sort | uniq -c

[root@centos7 ~]#last | grep -Eo "\<(([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>" | sort | uniq -c 1 127.0.0.1 1 192.168.1.102 1 192.168.1.103 1 192.168.1.108 1 192.168.1.110 37 192.168.30.1 1 192.168.30.133 1 192.168.30.139

 

方法三:

last | grep -Eo "\<(([1-9]?[0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>" | sort | uniq -c

[root@centos7 ~]#last | grep -Eo "\<(([1-9]?[0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>" | sort | uniq -c 1 127.0.0.1 2 192.168.1.102 1 192.168.1.103 1 192.168.1.108 1 192.168.1.110 37 192.168.30.1 2 192.168.30.133 1 192.168.30.139

 

 

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

0-9:

[0-9]

10-99:

[1-9][0-9]

100-199:

1[0-9][0-9]

200-249:

2[0-4][0-9]

250-255:

25[0-5]

 

 

二十一、显示ifconfig命令结果中所有IPv4地址

思路:

一定要加上\<\>进行单词锚定。

方法一:

ifconfig | grep -Eo "\<([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>"

[root@centos7 ~]#ifconfig | grep -Eo "\<([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>" 192.168.30.139 255.255.255.0 192.168.30.255 192.168.1.110 255.255.255.0 192.168.1.255 127.0.0.1 255.0.0.0 192.168.122.1 255.255.255.0 192.168.122.255

 

方法二:

ifconfig | grep -Eo "\<(([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>"

思路:

由于IP地址格式为X.X.X.X,前三处格式都为X.,可以使用{3}归纳。

[root@centos7 ~]#ifconfig | grep -Eo "\<(([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>" 192.168.30.139 255.255.255.0 192.168.30.255 192.168.1.110 255.255.255.0 192.168.1.255 127.0.0.1 255.0.0.0 192.168.122.1 255.255.255.0 192.168.122.255

 

方法三:

ifconfig | grep -Eo "\<(([1-9]?[0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>"

[root@centos7 ~]#ifconfig | grep -Eo "\<(([1-9]?[0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>" 192.168.30.139 255.255.255.0 192.168.30.255 192.168.1.110 255.255.255.0 192.168.1.255 127.0.0.1 255.0.0.0 192.168.122.1 255.255.255.0 192.168.122.255

 

 

二十二、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

echo "welcome to magedu linux" | grep -o "." | sort | uniq -c | sort -nr

[root@centos7 ~]#echo "welcome to magedu linux" | grep -o "." | sort | uniq -c | sort -nr 3 e 3 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

 

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