2018-03-14 Linux学习

Posted 2020-10-27

9.6 awk (上)

awk  示例

    head -n2 test.txt|awk -F ‘:‘ ‘{print $1}‘
    head -n2 test.txt|awk -F ‘:‘ ‘{print $0}‘
    awk -F ‘:‘ ‘{print $1"#"$2"#"$3"#"$4}‘
    awk ‘/oo/‘ test.txt
    awk -F ‘:‘ ‘$1 ~ /oo/‘ test.txt
    awk -F ‘:‘ ‘/root/ {print $1,$3} /test/ {print $1,$3}‘ test.txt
    awk -F ‘:‘ ‘$3=="0"‘ /etc/passwd
    awk -F ‘:‘ ‘$3>="500"‘ /etc/passwd
    awk -F ‘:‘ ‘$3>=500‘ /etc/passwd
    awk -F ‘:‘ ‘$7!="/sbin/nologin"‘ /etc/passwd

-F   以...为分隔符
无需加脱义字符
数学运算时，字符串需要加上双引号

        [[email protected] awk]# head -2 text.txt|awk -F ‘:‘ ‘{print $1}‘ 
        root
        bin

        [[email protected] awk]# head -2 text.txt|awk -F ‘:‘ ‘{print $0}‘ 
        root:x:0:0:root:/root:/bin/bash
        bin:x:1:1:bin:/bin:/sbin/nologin

        [[email protected] awk]# head -2 text.txt|awk -F ‘:‘ ‘{print $1"#"$2"#"$3}‘ 
        root#x#0
        bin#x#1

        [[email protected] awk]# awk ‘/roo/‘ text.txt 
        root:x:0:0:root:/root:/bin/bash
        operator:x:11:0:operator:/root:/sbin/nologin

        [[email protected] awk]# awk -F ‘:‘ ‘$1 ~ /roo/‘ text.txt 
        root:x:0:0:root:/root:/bin/bash

        [[email protected] awk]# awk -F ‘:‘ ‘/root/ {print $1,$3} /lp/ {print $1,$3,$4}‘ text.txt 
        root 0
        lp 4 7
        operator 11

        [[email protected] awk]# awk -F ‘:‘ ‘/root|lp/ {print $1,$3}‘ text.txt 
        root 0
        lp 4
        operator 11

        [[email protected] awk]# awk -F ‘:‘ ‘/root|lp/ {print $0}‘ text.txt 
        root:x:0:0:root:/root:/bin/bash
        lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
        operator:x:11:0:operator:/root:/sbin/nologin

        [[email protected] awk]# awk -F ‘:‘ ‘$3==0 {print $1}‘ text.txt 
        root

        [[email protected] awk]# awk -F ‘:‘ ‘$3>=500 {print $0}‘ text.txt 
        polkitd:x:999:997:User for polkitd:/:/sbin/nologin

        [[email protected] awk]# awk -F ‘:‘ ‘$7!="/sbin/nologin" {print $0}‘ text.txt 
        root:x:0:0:root:/root:/bin/bash
        sync:x:5:0:sync:/sbin:/bin/sync
        shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
        halt:x:7:0:halt:/sbin:/sbin/halt

9.7 awk (下)

OFS  打印时指定的分隔符
NR   行
NF   段

示例
    awk -F ‘:‘ ‘$3<$4‘ /etc/passwd
    awk -F ‘:‘ ‘$3>"5" && $3<"7"‘ /etc/passwd
    awk -F ‘:‘ ‘$3>1000 || $7=="/bin/bash"‘ /etc/passwd
    head -5 /etc/passwd | awk -F ‘:‘ ‘{OFS="#"} {print $1,$3,$4}‘
    awk -F ‘:‘ ‘{OFS="#"} {if ($3>500) {print $1,$2,$3,$4}}‘ /etc/passwd
    head -3 /etc/passwd | awk -F ‘:‘ ‘{print NF}‘
    head -3 /etc/passwd | awk -F ‘:‘ ‘{print NR}‘
    awk ‘NR>40‘ /etc/passwd
    awk -F ‘:‘ ‘NR<20 && $1 ~ /roo/‘ /etc/passwd
    head -n 3 /etc/passwd | awk -F ‘:‘ ‘$1="root"‘
    awk -F ‘:‘ ‘{(tot=tot+$3)}; END {print tot}‘ /etc/passwd
    awk -F ‘:‘ ‘{if($1=="root") {print $0}}‘ /etc/passwd

        [[email protected] awk]# awk -F ‘:‘ ‘$3<$4‘ text.txt 
        adm:x:3:4:adm:/var/adm:/sbin/nologin
        lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
        mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
        games:x:12:100:games:/usr/games:/sbin/nologin
        ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin

        [[email protected] awk]# awk -F ‘:‘ ‘$3>5 && $3<7‘ text.txt 
        shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown

        [[email protected] awk]# awk -F ‘:‘ ‘$3<5 && $7 ~ /bash/‘ text.txt 
        root:x:0:0:root:/root:/bin/bash

        [[email protected] awk]# awk -F ‘:‘ ‘{OFS="#"} $3>500 || $7 ~ /bash/ {print $1,$3,$7}‘ text.txt 
        root#0#/bin/bash
        polkitd#999#/sbin/nologin

        [[email protected] awk]# awk -F ‘:‘ ‘{OFS="#"} {if($3>500 && $7 ~ /nologin/) {print $1,$3,$7}}‘ text.txt 
        polkitd#999#/sbin/nologin

        [[email protected] awk]# awk -F ‘:‘ ‘NR<=3‘ text.txt 
        root:x:0:0:root:/root:/bin/bash
        bin:x:1:1:bin:/bin:/sbin/nologin
        daemon:x:2:2:daemon:/sbin:/sbin/nologin

        [[email protected] awk]# awk -F ‘:‘ ‘NR<=10 && $1 ~ /root|sync/‘ text.txt 
        root:x:0:0:root:/root:/bin/bash
        sync:x:5:0:sync:/sbin:/bin/sync

        [[email protected] awk]# head -3 text.txt | awk -F ‘:‘ ‘$1="root"‘
        root x 0 0 root /root /bin/bash
        root x 1 1 bin /bin /sbin/nologin
        root x 2 2 daemon /sbin /sbin/nologin

        [[email protected] awk]# awk -F ‘:‘ ‘{(tot=tot+$3)}; END {print tot}‘ text.txt 
        1788

        [[email protected] awk]# awk -F ‘:‘ ‘{if($1=="root") {print $0}}‘ text.txt 
        root:x:0:0:root:/root:/bin/bash