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  • sed练习题目

    1.11.8 sed练习题目

    1.用sed取出ifconfig中的ipv4地址

    [root@CentOS7 ~]# ifconfig|sed -nr '2s/^(.*inet )(.*)( netmask .*)$/2/p'
    192.168.110.131 
    

    2.显示/etc/passwd的最后一行

    [root@CentOS7 ~]# awk 'END{print$0}' /etc/passwd
    user6:x:4063:4067::/home/user6:/bin/bash
    [root@CentOS7 ~]# tail -n1 /etc/passwd
    user6:x:4063:4067::/home/user6:/bin/bash
    [root@CentOS7 ~]# sed -n '$p' /etc/passwd 
    user6:x:4063:4067::/home/user6:/bin/bash
    

    3.显示/etc/passwd的第一行到第三行

    [root@CentOS7 ~]# awk '{if (NR>=1 && NR<=3) print $0}' /etc/passwd 
    ##print 直接后跟变量名,不用加$,$0可以省略,if和()之间有无空格都可,()和print之间也一样
    root:x:0:0:root:/root:/bin/bash
    bin:x:1:1:bin:/bin:/sbin/nologin
    daemon:x:2:2:daemon:/sbin:/sbin/nologin
    [root@CentOS7 ~]#cat /etc/passwd | awk '{if(NR>=1 && NR<=3)print}' 
    root:x:0:0:root:/root:/bin/bash
    bin:x:1:1:bin:/bin:/sbin/nologin
    daemon:x:2:2:daemon:/sbin:/sbin/nologin
    [root@CentOS7 ~]# head -n3 /etc/passwd 
    root:x:0:0:root:/root:/bin/bash
    bin:x:1:1:bin:/bin:/sbin/nologin
    daemon:x:2:2:daemon:/sbin:/sbin/nologin
    [root@CentOS7 ~]# cat /etc/passwd |sed -n '1,3p'
    root:x:0:0:root:/root:/bin/bash
    bin:x:1:1:bin:/bin:/sbin/nologin
    daemon:x:2:2:daemon:/sbin:/sbin/nologin
    

    4.显示/etc/fstab 中以U开头的行

    [root@CentOS7 ~]# cat /etc/fstab |grep "^U"
    UUID=50ad6c96-3d5a-4840-9f52-11f045c46a1d /                       xfs     defaults        0 0
    UUID=755562ec-35e1-4ab9-bd08-8b0a691bde48 /boot                   xfs     defaults        0 0
    UUID=48c79d0b-623e-4a61-8b5e-da5b2f0050b6 /data                   xfs     defaults        0 0
    UUID=7067af7e-e829-49ba-b713-55296c046e27 swap                    swap    defaults        0 0
    UUID=d045c3b8-68ba-4479-9b98-ceec0c8aa526 /home               xfs     defaults         0 0
    [root@CentOS7 ~]# cat /etc/fstab |sed -nr '/^U/p'
    UUID=50ad6c96-3d5a-4840-9f52-11f045c46a1d /                       xfs     defaults        0 0
    UUID=755562ec-35e1-4ab9-bd08-8b0a691bde48 /boot                   xfs     defaults        0 0
    UUID=48c79d0b-623e-4a61-8b5e-da5b2f0050b6 /data                   xfs     defaults        0 0
    UUID=7067af7e-e829-49ba-b713-55296c046e27 swap                    swap    defaults        0 0
    UUID=d045c3b8-68ba-4479-9b98-ceec0c8aa526 /home               xfs     defaults         0 0
    [root@CentOS7 ~]# cat /etc/fstab |awk '/^U/{print}'
    UUID=50ad6c96-3d5a-4840-9f52-11f045c46a1d /                       xfs     defaults        0 0
    UUID=755562ec-35e1-4ab9-bd08-8b0a691bde48 /boot                   xfs     defaults        0 0
    UUID=48c79d0b-623e-4a61-8b5e-da5b2f0050b6 /data                   xfs     defaults        0 0
    UUID=7067af7e-e829-49ba-b713-55296c046e27 swap                    swap    defaults        0 0
    UUID=d045c3b8-68ba-4479-9b98-ceec0c8aa526 /home               xfs     defaults         0 0
    

    5.用sed的regex只显示ifconfig的第二行

    [root@CentOS7 ~]# ifconfig |sed -n '2p'
        inet 192.168.110.131  netmask 255.255.255.0  broadcast 192.168.110.255
    [root@CentOS7 ~]# ifconfig |head -n2 |tail -n1
        inet 192.168.110.131  netmask 255.255.255.0  broadcast 192.168.110.255
    [root@CentOS7 ~]# ifconfig |awk '{if (NR==2); print$0}' ##如果NR==2,后面什么都没跟,最后打印所有的行了,这里分号表示if语句结束了
    ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
            inet 192.168.110.131  netmask 255.255.255.0  broadcast 192.168.110.255
            inet6 fe80::6771:3c83:1113:d701  prefixlen 64  scopeid 0x20<link>
            ether 00:0c:29:8e:b3:16  txqueuelen 1000  (Ethernet)
            RX packets 137  bytes 16052 (15.6 KiB)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 59  bytes 9024 (8.8 KiB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
    ens37: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
            inet 172.20.129.161  netmask 255.255.0.0  broadcast 172.20.255.255
            inet6 fe80::4318:d843:7a34:9275  prefixlen 64  scopeid 0x20<link>
            ether 00:0c:29:8e:b3:20  txqueuelen 1000  (Ethernet)
            RX packets 22409  bytes 2432535 (2.3 MiB)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 5029  bytes 633655 (618.8 KiB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
    lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
            inet 127.0.0.1  netmask 255.0.0.0
            inet6 ::1  prefixlen 128  scopeid 0x10<host>
            loop  txqueuelen 1000  (Local Loopback)
            RX packets 50  bytes 5084 (4.9 KiB)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 50  bytes 5084 (4.9 KiB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
    [root@CentOS7 ~]# ifconfig |awk '{if (NR==2) print$0}'
            inet 192.168.110.131  netmask 255.255.255.0  broadcast 192.168.110.255
    

    6.只显示磁盘利用率

    [root@CentOS7 ~]# df |awk '//dev/sd/{print $1,$5}' ##$1和$5之间用,分隔,就表示空格
    /dev/sda2 10%
    /dev/sda6 1%
    /dev/sda3 1%
    /dev/sda1 16%
    [root@CentOS7 ~]# df |awk '//dev/sd/{print $1" "$5}' ##$1和$5之间加什么,用“内容”
    /dev/sda2 10%
    /dev/sda6 1%
    /dev/sda3 1%
    /dev/sda1 16%
    [root@CentOS7 ~]# df |awk -F "[ ]+" '//dev/sd/{print $1"="$5}'
    /dev/sda2=10%
    /dev/sda6=1%
    /dev/sda3=1%
    /dev/sda1=16%
    [root@CentOS7 ~]# df |awk -F "[[:space:]]+" '//dev/sd/{print $5}'
    10%
    1%
    1%
    16%
    [root@CentOS7 ~]# df |awk -F "[ ]+" '//dev/sd/{print $5}'
    10%
    1%
    1%
    16%
    

    7.显示从第一行往后的三行/etc/passwd

    [root@CentOS7 ~]# cat /etc/passwd |sed -n '1,+3p'
    root:x:0:0:root:/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
    [root@CentOS7 ~]# cat /etc/passwd |awk '{if(NR>=1 && NR<=4) print}'
    root:x:0:0:root:/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
    

    8.显示/etc/passwd从s开头的行到f开头之间的行

    [root@CentOS7 ~]# cat /etc/passwd |sed -n '/^s/,/^f/p'
    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
    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
    sssd:x:998:996:User for sssd:/:/sbin/nologin
    libstoragemgmt:x:997:994:daemon account for libstoragemgmt:/var/run/lsm:/sbin/nologin
    rpc:x:32:32:Rpcbind Daemon:/var/lib/rpcbind:/sbin/nologin
    colord:x:996:993:User for colord:/var/lib/colord:/sbin/nologin
    gluster:x:995:992:GlusterFS daemons:/var/run/gluster:/sbin/nologin
    saslauth:x:994:76:Saslauthd user:/run/saslauthd:/sbin/nologin
    abrt:x:173:173::/etc/abrt:/sbin/nologin
    setroubleshoot:x:993:990::/var/lib/setroubleshoot:/sbin/nologin
    rtkit:x:172:172:RealtimeKit:/proc:/sbin/nologin
    pulse:x:171:171:PulseAudio System Daemon:/var/run/pulse:/sbin/nologin
    chrony:x:992:987::/var/lib/chrony:/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
    unbound:x:991:986:Unbound DNS resolver:/etc/unbound:/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:990:984:User for geoclue:/var/lib/geoclue:/sbin/nologin
    radvd:x:75:75:radvd user:/:/sbin/nologin
    qemu:x:107:107:qemu user:/:/sbin/nologin
    ntp:x:38:38::/etc/ntp:/sbin/nologin
    gdm:x:42:42::/var/lib/gdm:/sbin/nologin
    gnome-initial-setup:x:989:983::/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
    tcpdump:x:72:72::/:/sbin/nologin
    zhu:x:1000:1000:zhu:/home/zhu:/bin/bash
    mandriva:x:4004:3004::/home/mandriva:/bin/bash
    fedora:x:2003:2003:Feora Community:/home/fedora:/bin/tcsh
    ssd:x:4058:4062::/home/ssd:/bin/bash
    memcached:x:987:981:Memcached daemon:/run/memcached:/sbin/nologin
    user2:x:4059:4063::/home/user2:/bin/sh
    user1:x:4060:4064::/home/user1:/bin/bash
    user3:x:4061:4065::/home/user3:/bin/bash
    user5:x:4062:4066::/home/user5:/bin/bash
    user6:x:4063:4067::/home/user6:/bin/bash
    

    9.显示/etc/passwd 第三行到f开头的行

    [root@CentOS7 ~]# cat /etc/passwd |sed -n '3,/^f/p'
    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
    

    10.只显示/etc/passwd偶数行

    [root@CentOS7 ~]# cat -n /etc/passwd |sed -n '2~2p'
         2	bin:x:1:1:bin:/bin:/sbin/nologin
         4	adm:x:3:4:adm:/var/adm:/sbin/nologin
         6	sync:x:5:0:sync:/sbin:/bin/sync
         8	halt:x:7:0:halt:/sbin:/sbin/halt
        10	operator:x:11:0:operator:/root:/sbin/nologin
        12	ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin
        14	systemd-network:x:192:192:systemd Network Management:/:/sbin/nologin
        16	polkitd:x:999:998:User for polkitd:/:/sbin/nologin
        18	libstoragemgmt:x:997:994:daemon account for libstoragemgmt:/var/run/lsm:/sbin/nologin
        20	colord:x:996:993:User for colord:/var/lib/colord:/sbin/nologin
        22	saslauth:x:994:76:Saslauthd user:/run/saslauthd:/sbin/nologin
        24	setroubleshoot:x:993:990::/var/lib/setroubleshoot:/sbin/nologin
        26	pulse:x:171:171:PulseAudio System Daemon:/var/run/pulse:/sbin/nologin
        28	rpcuser:x:29:29:RPC Service User:/var/lib/nfs:/sbin/nologin
        30	unbound:x:991:986:Unbound DNS resolver:/etc/unbound:/sbin/nologin
        32	usbmuxd:x:113:113:usbmuxd user:/:/sbin/nologin
        34	radvd:x:75:75:radvd user:/:/sbin/nologin
        36	ntp:x:38:38::/etc/ntp:/sbin/nologin
        38	gnome-initial-setup:x:989:983::/run/gnome-initial-setup/:/sbin/nologin
        40	avahi:x:70:70:Avahi mDNS/DNS-SD Stack:/var/run/avahi-daemon:/sbin/nologin
        42	tcpdump:x:72:72::/:/sbin/nologin
        44	mandriva:x:4004:3004::/home/mandriva:/bin/bash
        46	habse:x:988:982::/home/habse:/bin/nologin
        48	nginx:x:4029:4031::/home/nginx:/bin/bash
        50	git:x:4033:4036::/home/git:/bin/bash
        52	u:x:4036:4041::/home/u:/bin/bash
        54	tcsh:x:4038:4043::/home/tcsh:/sbin/nologin
        56	nologin:x:4040:4045::/home/nologin:/sbin/nologin
        58	basher:x:4042:4047::/home/basher:/sbin/nologin
        60	tomcat1:x:4047:4035::/home/tomcat1:/bin/bash
        62	wang:x:4049:4053::/home/wang:/bin/bash
        64	apache:x:80:80::/var/www:/sbin/nologin
        66	wan:x:4054:4058::/home/wan:/bin/bash
        68	wan1233:x:4056:4060::/home/wan1233:/bin/bash
        70	ssd:x:4058:4062::/home/ssd:/bin/bash
        72	user2:x:4059:4063::/home/user2:/bin/sh
        74	user3:x:4061:4065::/home/user3:/bin/bash
        76	user6:x:4063:4067::/home/user6:/bin/bash
    

    11.只显示/etc/passwd奇数行

    [root@CentOS7 ~]# cat -n /etc/passwd |sed -n '1~2p'
     1	root:x:0:0:root:/root:/bin/bash
     3	daemon:x:2:2:daemon:/sbin:/sbin/nologin
     5	lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
     7	shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
     9	mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
    11	games:x:12:100:games:/usr/games:/sbin/nologin
    13	nobody:x:99:99:Nobody:/:/sbin/nologin
    15	dbus:x:81:81:System message bus:/:/sbin/nologin
    17	sssd:x:998:996:User for sssd:/:/sbin/nologin
    19	rpc:x:32:32:Rpcbind Daemon:/var/lib/rpcbind:/sbin/nologin
    21	gluster:x:995:992:GlusterFS daemons:/var/run/gluster:/sbin/nologin
    23	abrt:x:173:173::/etc/abrt:/sbin/nologin
    25	rtkit:x:172:172:RealtimeKit:/proc:/sbin/nologin
    27	chrony:x:992:987::/var/lib/chrony:/sbin/nologin
    29	nfsnobody:x:65534:65534:Anonymous NFS User:/var/lib/nfs:/sbin/nologin
    31	tss:x:59:59:Account used by the trousers package to sandbox the tcsd daemon:/dev/null:/sbin/nologin
    33	geoclue:x:990:984:User for geoclue:/var/lib/geoclue:/sbin/nologin
    35	qemu:x:107:107:qemu user:/:/sbin/nologin
    37	gdm:x:42:42::/var/lib/gdm:/sbin/nologin
    39	sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin
    41	postfix:x:89:89::/var/spool/postfix:/sbin/nologin
    43	zhu:x:1000:1000:zhu:/home/zhu:/bin/bash
    45	fedora:x:2003:2003:Feora Community:/home/fedora:/bin/tcsh
    47	gentoo:x:4028:4029:Gentoo Distribution:/home/gentoo:/bin/csh
    49	varnish:x:4030:4032::/home/varnish:/bin/bash
    51	mage:x:4035:4039::/home/mage:/bin/bash
    53	bash:x:4037:4042::/home/bash:/bin/bash
    55	testbash:x:4039:4044::/home/testbash:/sbin/nologin
    57	userbasher:x:4041:4046::/home/userbasher:/bin/bash
    59	user:x:4043:4048::/home/user:/bin/bash
    61	mysql1:x:4048:4052::/home/mysql1:/bin/bash
    63	userdf:x:4050:4054::/home/userdf:/bin/bash
    65	user112:x:4053:4057::/home/user112:/bin/bash
    67	wan1:x:4055:4059::/home/wan1:/bin/bash
    69	usd:x:4057:4061::/home/usd:/bin/bash
    71	memcached:x:987:981:Memcached daemon:/run/memcached:/sbin/nologin
    73	user1:x:4060:4064::/home/user1:/bin/bash
    75	user5:x:4062:4066::/home/user5:/bin/bash
    

    12.删除/etc/passwd第二行到第10行

    [root@CentOS7 ~]# cat -n /etc/passwd |sed -n '2,10d;p'
         1	root:x:0:0:root:/root:/bin/bash
        11	games:x:12:100:games:/usr/games:/sbin/nologin
        12	ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin
        13	nobody:x:99:99:Nobody:/:/sbin/nologin
        14	systemd-network:x:192:192:systemd Network Management:/:/sbin/nologin
        15	dbus:x:81:81:System message bus:/:/sbin/nologin
        16	polkitd:x:999:998:User for polkitd:/:/sbin/nologin
        17	sssd:x:998:996:User for sssd:/:/sbin/nologin
        18	libstoragemgmt:x:997:994:daemon account for libstoragemgmt:/var/run/lsm:/sbin/nologin
        19	rpc:x:32:32:Rpcbind Daemon:/var/lib/rpcbind:/sbin/nologin
        20	colord:x:996:993:User for colord:/var/lib/colord:/sbin/nologin
        21	gluster:x:995:992:GlusterFS daemons:/var/run/gluster:/sbin/nologin
        22	saslauth:x:994:76:Saslauthd user:/run/saslauthd:/sbin/nologin
        23	abrt:x:173:173::/etc/abrt:/sbin/nologin
        24	setroubleshoot:x:993:990::/var/lib/setroubleshoot:/sbin/nologin
        25	rtkit:x:172:172:RealtimeKit:/proc:/sbin/nologin
        26	pulse:x:171:171:PulseAudio System Daemon:/var/run/pulse:/sbin/nologin
        27	chrony:x:992:987::/var/lib/chrony:/sbin/nologin
        28	rpcuser:x:29:29:RPC Service User:/var/lib/nfs:/sbin/nologin
        29	nfsnobody:x:65534:65534:Anonymous NFS User:/var/lib/nfs:/sbin/nologin
        30	unbound:x:991:986:Unbound DNS resolver:/etc/unbound:/sbin/nologin
        31	tss:x:59:59:Account used by the trousers package to sandbox the tcsd daemon:/dev/null:/sbin/nologin
        32	usbmuxd:x:113:113:usbmuxd user:/:/sbin/nologin
        33	geoclue:x:990:984:User for geoclue:/var/lib/geoclue:/sbin/nologin
        34	radvd:x:75:75:radvd user:/:/sbin/nologin
        35	qemu:x:107:107:qemu user:/:/sbin/nologin
        36	ntp:x:38:38::/etc/ntp:/sbin/nologin
        37	gdm:x:42:42::/var/lib/gdm:/sbin/nologin
        38	gnome-initial-setup:x:989:983::/run/gnome-initial-setup/:/sbin/nologin
        39	sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin
        40	avahi:x:70:70:Avahi mDNS/DNS-SD Stack:/var/run/avahi-daemon:/sbin/nologin
        41	postfix:x:89:89::/var/spool/postfix:/sbin/nologin
        42	tcpdump:x:72:72::/:/sbin/nologin
        43	zhu:x:1000:1000:zhu:/home/zhu:/bin/bash
        44	mandriva:x:4004:3004::/home/mandriva:/bin/bash
        45	fedora:x:2003:2003:Feora Community:/home/fedora:/bin/tcsh
        46	habse:x:988:982::/home/habse:/bin/nologin
        47	gentoo:x:4028:4029:Gentoo Distribution:/home/gentoo:/bin/csh
        48	nginx:x:4029:4031::/home/nginx:/bin/bash
        49	varnish:x:4030:4032::/home/varnish:/bin/bash
        50	git:x:4033:4036::/home/git:/bin/bash
        51	mage:x:4035:4039::/home/mage:/bin/bash
        52	u:x:4036:4041::/home/u:/bin/bash
        53	bash:x:4037:4042::/home/bash:/bin/bash
        54	tcsh:x:4038:4043::/home/tcsh:/sbin/nologin
        55	testbash:x:4039:4044::/home/testbash:/sbin/nologin
        56	nologin:x:4040:4045::/home/nologin:/sbin/nologin
        57	userbasher:x:4041:4046::/home/userbasher:/bin/bash
        58	basher:x:4042:4047::/home/basher:/sbin/nologin
        59	user:x:4043:4048::/home/user:/bin/bash
        60	tomcat1:x:4047:4035::/home/tomcat1:/bin/bash
        61	mysql1:x:4048:4052::/home/mysql1:/bin/bash
        62	wang:x:4049:4053::/home/wang:/bin/bash
        63	userdf:x:4050:4054::/home/userdf:/bin/bash
        64	apache:x:80:80::/var/www:/sbin/nologin
        65	user112:x:4053:4057::/home/user112:/bin/bash
        66	wan:x:4054:4058::/home/wan:/bin/bash
        67	wan1:x:4055:4059::/home/wan1:/bin/bash
        68	wan1233:x:4056:4060::/home/wan1233:/bin/bash
        69	usd:x:4057:4061::/home/usd:/bin/bash
        70	ssd:x:4058:4062::/home/ssd:/bin/bash
        71	memcached:x:987:981:Memcached daemon:/run/memcached:/sbin/nologin
        72	user2:x:4059:4063::/home/user2:/bin/sh
        73	user1:x:4060:4064::/home/user1:/bin/bash
        74	user3:x:4061:4065::/home/user3:/bin/bash
        75	user5:x:4062:4066::/home/user5:/bin/bash
        76	user6:x:4063:4067::/home/user6:/bin/bash
    

    13.在/etc/passwd 中1~20行每行后追加新行new line

    [root@CentOS7 ~]# cat -n /etc/passwd |sed  '1,20a 
    ew line'
         1	root:x:0:0:root:/root:/bin/bash
    new line
         2	bin:x:1:1:bin:/bin:/sbin/nologin
    new line
         3	daemon:x:2:2:daemon:/sbin:/sbin/nologin
    new line
         4	adm:x:3:4:adm:/var/adm:/sbin/nologin
    new line
         5	lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
    new line
         6	sync:x:5:0:sync:/sbin:/bin/sync
    new line
         7	shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
    new line
         8	halt:x:7:0:halt:/sbin:/sbin/halt
    new line
         9	mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
    new line
        10	operator:x:11:0:operator:/root:/sbin/nologin
    new line
        11	games:x:12:100:games:/usr/games:/sbin/nologin
    new line
        12	ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin
    new line
        13	nobody:x:99:99:Nobody:/:/sbin/nologin
    new line
        14	systemd-network:x:192:192:systemd Network Management:/:/sbin/nologin
    new line
        15	dbus:x:81:81:System message bus:/:/sbin/nologin
    new line
        16	polkitd:x:999:998:User for polkitd:/:/sbin/nologin
    new line
        17	sssd:x:998:996:User for sssd:/:/sbin/nologin
    new line
        18	libstoragemgmt:x:997:994:daemon account for libstoragemgmt:/var/run/lsm:/sbin/nologin
    new line
        19	rpc:x:32:32:Rpcbind Daemon:/var/lib/rpcbind:/sbin/nologin
    new line
        20	colord:x:996:993:User for colord:/var/lib/colord:/sbin/nologin
    new line
    

    14.在.bashrc 的Source下面加一行newline

    [root@CentOS7 ~]# sed  '/Source/a 
    ewline' .bashrc
    # .bashrc
    # User specific aliases and functions
    alias rm='rm -i'
    alias cp='cp -i'
    alias mv='mv -i'
    alias mancn='man -M /usr/man/zh_CN'
    # Source global definitions
    newline
    if [ -f /etc/bashrc ]; then
    	. /etc/bashrc
    fi
    alias cdnet='cd /etc/sysconfig/network-scripts'
    LANG=en_US.utf8
    

    前面加一行

    [root@CentOS7 ~]# sed  '/Source/i 
    ewline' .bashrc
    # .bashrc
    # User specific aliases and functions
    alias rm='rm -i'
    alias cp='cp -i'
    alias mv='mv -i'
    alias mancn='man -M /usr/man/zh_CN'
    newline
    # Source global definitions
    if [ -f /etc/bashrc ]; then
    	. /etc/bashrc
    fi
    alias cdnet='cd /etc/sysconfig/network-scripts'
    LANG=en_US.utf8
    

    加2行

    [root@CentOS7 ~]# sed  '/Source/i 
    ewline 
    newline2' .bashrc
    # .bashrc
    # User specific aliases and functions
    alias rm='rm -i'
    alias cp='cp -i'
    alias mv='mv -i'
    alias mancn='man -M /usr/man/zh_CN'
    newline 
    newline2
    # Source global definitions
    if [ -f /etc/bashrc ]; then
    	. /etc/bashrc
    fi
    alias cdnet='cd /etc/sysconfig/network-scripts'
    LANG=en_US.utf8
    

    替换source这行

    [root@CentOS7 ~]# sed  '/Source/c 
    ewline' .bashrc
    # .bashrc
    # User specific aliases and functions
    alias rm='rm -i'
    alias cp='cp -i'
    alias mv='mv -i'
    alias mancn='man -M /usr/man/zh_CN'
    newline
    if [ -f /etc/bashrc ]; then
    	. /etc/bashrc
    fi
    alias cdnet='cd /etc/sysconfig/network-scripts'
    LANG=en_US.utf8
    

    15.把/etc/fstab中UUID开头的行,过渡出来,写到新文件/root/f1中

    [root@CentOS7 ~]# cat /etc/fstab |sed '/^UUID/w /root/f1'
    #
    # /etc/fstab
    # Created by anaconda on Wed Jul 18 17:26:27 2018
    #
    # Accessible filesystems, by reference, are maintained under '/dev/disk'
    # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
    #
    UUID=50ad6c96-3d5a-4840-9f52-11f045c46a1d /                       xfs     defaults        0 0
    UUID=755562ec-35e1-4ab9-bd08-8b0a691bde48 /boot                   xfs     defaults        0 0
    UUID=48c79d0b-623e-4a61-8b5e-da5b2f0050b6 /data                   xfs     defaults        0 0
    UUID=7067af7e-e829-49ba-b713-55296c046e27 swap                    swap    defaults        0 0
    UUID=d045c3b8-68ba-4479-9b98-ceec0c8aa526 /home               xfs     defaults         0 0
    [root@CentOS7 ~]# cat f1
    UUID=50ad6c96-3d5a-4840-9f52-11f045c46a1d /                       xfs     defaults        0 0
    UUID=755562ec-35e1-4ab9-bd08-8b0a691bde48 /boot                   xfs     defaults        0 0
    UUID=48c79d0b-623e-4a61-8b5e-da5b2f0050b6 /data                   xfs     defaults        0 0
    UUID=7067af7e-e829-49ba-b713-55296c046e27 swap                    swap    defaults        0 0
    UUID=d045c3b8-68ba-4479-9b98-ceec0c8aa526 /home               xfs     defaults         0 0
    

    16.在UUID开头的行后面读入/etc/issue文件的内容

    [root@CentOS7 ~]# cat /etc/fstab |sed '/^UUID/r /etc/issue'
    #
    # /etc/fstab
    # Created by anaconda on Wed Jul 18 17:26:27 2018
    #
    # Accessible filesystems, by reference, are maintained under '/dev/disk'
    # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
    #
    UUID=50ad6c96-3d5a-4840-9f52-11f045c46a1d /                       xfs     defaults        0 0
    the tty is l
    the hostname is 
    
    the current time is 	
    S
    Kernel 
     on an m
    UUID=755562ec-35e1-4ab9-bd08-8b0a691bde48 /boot                   xfs     defaults        0 0
    the tty is l
    the hostname is 
    
    the current time is 	
    S
    Kernel 
     on an m
    UUID=48c79d0b-623e-4a61-8b5e-da5b2f0050b6 /data                   xfs     defaults        0 0
    the tty is l
    the hostname is 
    
    the current time is 	
    S
    Kernel 
     on an m
    UUID=7067af7e-e829-49ba-b713-55296c046e27 swap                    swap    defaults        0 0
    the tty is l
    the hostname is 
    
    the current time is 	
    S
    Kernel 
     on an m
    UUID=d045c3b8-68ba-4479-9b98-ceec0c8aa526 /home               xfs     defaults         0 0
    the tty is l
    the hostname is 
    
    the current time is 	
    S
    Kernel 
     on an m
    

    17.为被regex匹配到的行打印行号

    [root@CentOS7 ~]# cat /etc/fstab |sed '/^UUID/= '
    #
    # /etc/fstab
    # Created by anaconda on Wed Jul 18 17:26:27 2018
    #
    # Accessible filesystems, by reference, are maintained under '/dev/disk'
    # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
    #
    9
    UUID=50ad6c96-3d5a-4840-9f52-11f045c46a1d /                       xfs     defaults        0 0
    10
    UUID=755562ec-35e1-4ab9-bd08-8b0a691bde48 /boot                   xfs     defaults        0 0
    11
    UUID=48c79d0b-623e-4a61-8b5e-da5b2f0050b6 /data                   xfs     defaults        0 0
    12
    UUID=7067af7e-e829-49ba-b713-55296c046e27 swap                    swap    defaults        0 0
    13
    UUID=d045c3b8-68ba-4479-9b98-ceec0c8aa526 /home               xfs     defaults         0 0
    

    18.除了模式空间的行其他行的行号全显示出来

    [root@CentOS7 ~]# cat /etc/fstab |sed '/^UUID/d;= '
    1
    
    2
    #
    3
    # /etc/fstab
    4
    # Created by anaconda on Wed Jul 18 17:26:27 2018
    5
    #
    6
    # Accessible filesystems, by reference, are maintained under '/dev/disk'
    7
    # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
    8
    #
    14
    

    19.除了第3行,其他都打印(有行号)

    [root@CentOS7 ~]# cat /etc/fstab |sed '3d;='
    1
    2
    #
    4
    # Created by anaconda on Wed Jul 18 17:26:27 2018
    5
    #
    6
    # Accessible filesystems, by reference, are maintained under '/dev/disk'
    7
    # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
    8
    #
    9
    UUID=50ad6c96-3d5a-4840-9f52-11f045c46a1d /                       xfs     defaults        0 0
    10
    UUID=755562ec-35e1-4ab9-bd08-8b0a691bde48 /boot                   xfs     defaults        0 0
    11
    UUID=48c79d0b-623e-4a61-8b5e-da5b2f0050b6 /data                   xfs     defaults        0 0
    12
    UUID=7067af7e-e829-49ba-b713-55296c046e27 swap                    swap    defaults        0 0
    13
    UUID=d045c3b8-68ba-4479-9b98-ceec0c8aa526 /home               xfs     defaults         0 0
    14
    
    [root@CentOS7 ~]# cat -n /etc/fstab |sed -n '3d;p'
     1	
     2	#
     4	# Created by anaconda on Wed Jul 18 17:26:27 2018
     5	#
     6	# Accessible filesystems, by reference, are maintained under '/dev/disk'
     7	# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
     8	#
     9	UUID=50ad6c96-3d5a-4840-9f52-11f045c46a1d /                       xfs     defaults        0 0
    10	UUID=755562ec-35e1-4ab9-bd08-8b0a691bde48 /boot                   xfs     defaults        0 0
    11	UUID=48c79d0b-623e-4a61-8b5e-da5b2f0050b6 /data                   xfs     defaults        0 0
    12	UUID=7067af7e-e829-49ba-b713-55296c046e27 swap                    swap    defaults        0 0
    13	UUID=d045c3b8-68ba-4479-9b98-ceec0c8aa526 /home               xfs     defaults         0 0
    14	
    [root@CentOS7 ~]# cat -n /etc/fstab |sed -n '3!p'
         1	
         2	#
         4	# Created by anaconda on Wed Jul 18 17:26:27 2018
         5	#
         6	# Accessible filesystems, by reference, are maintained under '/dev/disk'
         7	# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
         8	#
         9	UUID=50ad6c96-3d5a-4840-9f52-11f045c46a1d /                       xfs     defaults        0 0
        10	UUID=755562ec-35e1-4ab9-bd08-8b0a691bde48 /boot                   xfs     defaults        0 0
        11	UUID=48c79d0b-623e-4a61-8b5e-da5b2f0050b6 /data                   xfs     defaults        0 0
        12	UUID=7067af7e-e829-49ba-b713-55296c046e27 swap                    swap    defaults        0 0
        13	UUID=d045c3b8-68ba-4479-9b98-ceec0c8aa526 /home               xfs     defaults         0 0
        14	
    

    21.将root替换为ROOT,将r..t替换为haha,在r..t后面加er,如rooter
    ,要求将/etc/default/grub 中的LINUX那行quiet后加net.ifnames=0
    GRUB_CMDLINE_LINUX="crashkernel=auto rhgb quiet"

    [root@CentOS7 ~]# cat /etc/passwd |sed -nr 's/r..t>/ROOT/pg'
    ROOT:x:0:0:ROOT:/ROOT:/bin/bash
    operator:x:11:0:operator:/ROOT:/sbin/nologin
    [root@CentOS7 ~]# cat /etc/passwd |sed -nr 's/r..t>/haha/pg'
    haha:x:0:0:haha:/haha:/bin/bash
    operator:x:11:0:operator:/haha:/sbin/nologin
    [root@CentOS7 ~]# cat /etc/passwd |sed -nr 's/(r..t>)/1er/pg'
    rooter:x:0:0:rooter:/rooter:/bin/bash
    operator:x:11:0:operator:/rooter:/sbin/nologin
    [root@CentOS7 ~]#  cat /etc/default/grub|sed -n '/LINUX/s/"$/ net.ifnames=0"/p'
    GRUB_CMDLINE_LINUX="crashkernel=auto rhgb quiet net.ifnames=0"
    [root@CentOS7 ~]# cat /etc/default/grub|sed -nr 's/^(.*quiet)/1 net.ifname=0/p'
    GRUB_CMDLINE_LINUX="crashkernel=auto rhgb quiet net.ifname=0"
    

    22.使用sed取出IPV4的地址(至少5种方法)

    [root@CentOS7 ~]# ifconfig |head -n2 |tail -n1  |tr -s ' ' |cut -d' ' -f3
    192.168.110.131
    [root@CentOS7 ~]# ifconfig ens33 |grep -w inet |tr -s ' ' |cut -d" " -f3
    192.168.110.131
    [root@CentOS7 ~]# ifconfig ens33 |sed -nr 's/^(.*inet )(.*)( netmask.*)$/2/p'
    192.168.110.131 
    [root@CentOS7 ~]# ifconfig ens33 |awk -F "[[:space:]]+" '{if(NR==2) print $3}'
    192.168.110.131
    [root@CentOS7 ~]# ifconfig ens33 |awk   '{if(NR==2) print $2}'##-F "[[:space:]]+"等价于FS="[ ]+"
    192.168.110.131
    [root@CentOS7 ~]# ifconfig ens33 |awk  '{FS="[ ]+"; if(NR==2) print $3}'
    192.168.110.131
    [root@CentOS7 ~]# ifconfig ens33 |sed '2!d;s/^.*inet//;s/ netmask.*//'
    192.168.110.131 
    [root@CentOS7 ~]# ifconfig ens33 |sed -nr '2s/.* inet (.*) netmask.*/1/p'
    192.168.110.131 
    

    23.将一个命令的执行结果进行压缩,重定向到压缩文件中

    [root@CentOS7 ~]# ls |xargs tar zcf root.tar.gz 
    [root@CentOS7 ~]# tar ft root.tar.gz 
    1.sh
    b
    Desktop/
    Documents/
    Downloads/
    f1
    f2
    initial-setup-ks.cfg
    Music/
    Pictures/
    Pictures/Screenshot from 2018-07-21 08-45-39.png
    Public/
    root.tar.gz
    space.txt
    Templates/
    test.txt
    Videos/
    

    24.多点编辑将/etc/passwd 中空行及空行的行号打印出来

    25.取出/etc/sysconfig/network-scripts/ 中的基名和目录名

    [root@CentOS7 ~]# basename /etc/sysconfig/network-scripts/
    network-scripts
    [root@CentOS7 ~]# dirname  /etc/sysconfig/network-scripts/
    /etc/sysconfig
    [root@CentOS7 ~]#echo "/etc/sysconfig/network-scripts/"|grep -Eo "[^/]+/?$"
    network-scripts/
    [root@CentOS7 ~]# echo "/etc/sysconfig/network-scripts/"|sed -r 's/^(.*/)([^/]+/?)/2/'
    network-scripts/
    [root@CentOS7 ~]# echo "/etc/sysconfig/network-scripts/"|sed -r 's/^(.*/)([^/]+/?)/1/'
    /etc/sysconfig/
    [root@CentOS7 ~]# echo "/etc/sysconfig/network-scripts"|sed -r 's/^(.*/)([^/]+/?)/2/'
    network-scripts
    

    26.去掉centos6中的/etc/httpd/conf/httpd.conf

    <VirtualHost*:80> 到#中的每行开头的#号

    [root@CentOS6 ~]# cat /etc/httpd/conf/httpd.conf |sed -r
    '/^#<VirtualHost/,/^#</VirtualHost/s/#//'
    <VirtualHost *:80>
        ServerAdmin webmaster@dummy-host.example.com
        DocumentRoot /www/docs/dummy-host.example.com
        ServerName dummy-host.example.com
        ErrorLog logs/dummy-host.example.com-error_log
        CustomLog logs/dummy-host.example.com-access_log common
    </VirtualHost>
    

    27.将/etc/fstab中开头不是#加上#

        [root@CentOS6 ~]# cat /etc/fstab |sed -r 's/^([^#].*)/#1/'
        
        #
        # /etc/fstab
        # Created by anaconda on Wed Jul 18 17:13:36 2018
        #
        # Accessible filesystems, by reference, are maintained under '/dev/disk'
        # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
        #
        #UUID=959dbbae-a23d-4e36-a306-00ffeeb0ac35 /                       ext4    defaults        1 1
        #UUID=204cb4a7-64cd-4d54-8757-4abaedf6564c /boot                   ext4    defaults        1 2
        #UUID=31ab6aee-936c-4aa4-92e3-31f6348c976c /data                   ext4    defaults        1 2
        #UUID=ccb69c46-a8b7-46ec-9015-56656319c72a swap                    swap    defaults        0 0
        #tmpfs                   /dev/shm                tmpfs   defaults        0 0
        #devpts                  /dev/pts                devpts  gid=5,mode=620  0 0
        #sysfs                   /sys                    sysfs   defaults        0 0
        #proc                    /proc                   proc    defaults        0 0
    
    [root@centos7 ~]# cat /etc/fstab |sed -r 's/^([^#].*)/#&/'
    #
    # /etc/fstab
    # Created by anaconda on Sat Aug 18 23:02:43 2018
    #
    # Accessible filesystems, by reference, are maintained under '/dev/disk'
    # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
    #
    #UUID=d9c33ebe-7198-496d-9211-468ed2aff31d /                       xfs     defaults        0 0
    #UUID=61e1da9b-93da-4aa7-bc62-148e74505ccf /boot                   xfs     defaults        0 0
    #UUID=d4001f2b-fe46-4479-aaf4-59ecce51eb95 /data                   xfs     defaults        0 0
    #UUID=d0c3c003-2fb6-453c-8c74-fc3c1b1acaf8 swap                    swap    defaults        0 0
    

    28.将/etc/fstab中的小写字母转换成大写字母

    [root@centos7 ~]# cat /etc/fstab |sed -r 's/[[:alpha:]]/u&/g'
    #
    # /ETC/FSTAB
    # CREATED BY ANACONDA ON SAT AUG 18 23:02:43 2018
    #
    # ACCESSIBLE FILESYSTEMS, BY REFERENCE, ARE MAINTAINED UNDER '/DEV/DISK'
    # SEE MAN PAGES FSTAB(5), FINDFS(8), MOUNT(8) AND/OR BLKID(8) FOR MORE INFO
    #
    UUID=D9C33EBE-7198-496D-9211-468ED2AFF31D /                       XFS     DEFAULTS        0 0
    UUID=61E1DA9B-93DA-4AA7-BC62-148E74505CCF /BOOT                   XFS     DEFAULTS        0 0
    UUID=D4001F2B-FE46-4479-AAF4-59ECCE51EB95 /DATA                   XFS     DEFAULTS        0 0
    UUID=D0C3C003-2FB6-453C-8C74-FC3C1B1ACAF8 SWAP                    SWAP    DEFAULTS        0 0
    
    [root@centos7 ~]# cat /etc/fstab |sed -r 's/[[:alpha:]]/u&/g'|sed -r 's/[[:alpha:]]/l&/g'
    ##l 表示小写u表示大写&引用前面被正则匹配到的
    #
    # /etc/fstab
    # created by anaconda on sat aug 18 23:02:43 2018
    #
    # accessible filesystems, by reference, are maintained under '/dev/disk'
    # see man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
    #
    uuid=d9c33ebe-7198-496d-9211-468ed2aff31d /                       xfs     defaults        0 0
    uuid=61e1da9b-93da-4aa7-bc62-148e74505ccf /boot                   xfs     defaults        0 0
    uuid=d4001f2b-fe46-4479-aaf4-59ecce51eb95 /data                   xfs     defaults        0 0
    uuid=d0c3c003-2fb6-453c-8c74-fc3c1b1acaf8 swap                    swap    defaults        0 0
    

    29.将sed的一串代码放到文件中 ’s///‘,从文件中读取正则来执行

    [root@centos7 ~]# cat sed.script
    s/[[:alpha:]]/u&/g
    [root@centos7 ~]# sed -r -f sed.script /etc/fstab
    #
    # /ETC/FSTAB
    # CREATED BY ANACONDA ON SAT AUG 18 23:02:43 2018
    #
    # ACCESSIBLE FILESYSTEMS, BY REFERENCE, ARE MAINTAINED UNDER '/DEV/DISK'
    # SEE MAN PAGES FSTAB(5), FINDFS(8), MOUNT(8) AND/OR BLKID(8) FOR MORE INFO
    #
    UUID=D9C33EBE-7198-496D-9211-468ED2AFF31D /                       XFS     DEFAULTS        0 0
    UUID=61E1DA9B-93DA-4AA7-BC62-148E74505CCF /BOOT                   XFS     DEFAULTS        0 0
    UUID=D4001F2B-FE46-4479-AAF4-59ECCE51EB95 /DATA                   XFS     DEFAULTS        0 0
    UUID=D0C3C003-2FB6-453C-8C74-FC3C1B1ACAF8 SWAP                    SWAP    DEFAULTS        0 0
    [root@centos7 ~]# 
    

    30.将/eec/selinux/config 中的SELINUX=enforcing 改为SELINUX=disabled

    [root@centos7 ~]# cat /etc/selinux/config |sed -i 's/SELINUX=enforcing/SELINUX=disabled/'
    sed: no input files
    [root@centos7 ~]# sed -i 's/SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config
    [root@centos7 ~]# cat /etc/selinux/config
    # This file controls the state of SELinux on the system.
    # SELINUX= can take one of these three values:
    #     enforcing - SELinux security policy is enforced.
    #     permissive - SELinux prints warnings instead of enforcing.
    #     disabled - No SELinux policy is loaded.
    SELINUX=disabled
    # SELINUXTYPE= can take one of three two values:
    #     targeted - Targeted processes are protected,
    #     minimum - Modification of targeted policy. Only selected processes are protected. 
    #     mls - Multi Level Security protection.
    SELINUXTYPE=targeted 
    

    31.取出版本号

    [root@centos7 etc]# cat /etc/centos-release|sed -r 's/[^0-9]+([0-9]+).*/1/'
    7
    [root@centos7 etc]# cat /etc/centos-release|sed -r 's/[^[:digit:]]+([[:digit:]]+).*/1/'
    7
    [root@centos7 etc]# cat /etc/centos-release|awk -F "[ .]" '{print $4}'
    

    32 删除/etc/httpd/conf/httpd.conf 以空格+#号开头的无用行,以及空行

    [root@CentOS6 ~]# sed '/^$/d;/^[ ]*#/d' /etc/httpd/conf/httpd.conf
    

    33将奇数行和偶数行合并

    [root@centos7 etc]# seq 1 10|sed -r 'N;s#
    ##' 
    12
    34
    56
    78
    910
    
    1.awk 'NR%2==1' file  / /显示奇数行
    2.sed -n '1,$n;p' file   / /显示偶数行
    3.sed -n '1,$p;n' file / /显示奇数行
    4.奇数行:sed '2~2d' file / /显示奇数行
    5.偶数行:sed '1~2d' file/ /显示偶数行
    

    34、删除centos7系统/etc/grub2.cfg文件中所有以空白开头的行行首的空白字符

    35、删除/etc/fstab文件中所有以#开头,后面至少跟一个空白字符的行的行首的# 和空白字符

    36、在centos6系统/root/install.log每一行行首增加#号

    37、在/etc/fstab文件中不以#开头的行的行首增加#号

    38、处理/etc/fstab路径,使用sed命令取出其目录名和基名

    39、利用sed 取出ifconfig命令中本机的IPv4地址 7、统计centos安装光盘中Package目录下的所有rpm文件的以.分隔倒数第二个 字段的重复次数

    41、统计/etc/init.d/functions文件中每个单词的出现次数,并排序(用grep和 sed两种方法分别实现)

    42、将文本文件的n和n+1行合并为一行,n为奇数行
    seq 1 10|sed 'N;s/ //'

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  • 原文地址:https://www.cnblogs.com/huangsefeizhu/p/11506801.html
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