grep
Common options
optiondescribesupplement-EExtended regular (ERE)–extended–regexp-PBuilt in regularPerl-iignore case–ignore–case-nPrint line number–line–number-oPrint only matching content–only–matching-cPrint only the number of lines that match each file–count-BPrint the first few lines that match–before–context=NUM-APrint the last few lines that match–after–context=NUM-CPrint the first and last lines of the match–context=NUM–color=autoHighlight matchesDefault settings-vReverse to print unmatched lines–invert–match-eMultipoint operationUse with regular expressions
Basic regularity Symboldescriberemarks.Match any single character (must exist)^Matches a line that begins with a character$A line ending with what character^$Match blank lines*Matches the previous character 0 or more times.*Represents any character of any length[list]Match any single character in the list[ ^list]Match any single character in the list^[list]Matches characters that begin with any single character in the list^[ ^list]Matches the beginning of any single character except the list<What does it start withThere are in the symbol\>What does it end withThere are in the symbol\<>Exact matchThere are in the symbol\Matches the preceding character n consecutive timesThere are in the symbol\Matches the preceding character at least n timesThere are in the symbol\Indicates that the matching character appears at least m times and at most n timesThere are in the symbol\(strings)Save the matched characters, which can be replaced by the label \ 1There are in the symbol\ Perl built-in regular (- P) Symboldescriberemarks\dMatch number[0-9]\wMatch alphanumeric underscores[a-zA-Z0-9_]\sMatch spaces, tabs, page breaks[\t\r\n] Extended regular expression (- E) Symboldescriberemarks+Matches one or more preceding characters?Matches zero or one preceding character|or()Group character(taobao|baidui).comThe leading character is repeated n timesNot in symbol\The leading character is repeated at least n timesNot in symbol\The leading character is repeated n to m timesNot in symbol\ Case: remove all comments and blank lines when viewing the configuration file[root@server1 ~]# grep -Ev "^#|^$" /etc/ssh/sshd_config HostKey /etc/ssh/ssh_host_rsa_key HostKey /etc/ssh/ssh_host_ecdsa_key HostKey /etc/ssh/ssh_host_ed25519_key SyslogFacility AUTHPRIV AuthorizedKeysFile .ssh/authorized_keys PasswordAuthentication yes ChallengeResponseAuthentication no GSSAPIAuthentication yes GSSAPICleanupCredentials no UsePAM yes X11Forwarding yes AcceptEnv LANG LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES AcceptEnv LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT AcceptEnv LC_IDENTIFICATION LC_ALL LANGUAGE AcceptEnv XMODIFIERS Subsystem sftp /usr/libexec/openssh/sftp-server
sed
summary
- You can edit files non interactively, which is often used in shell scripts
- sed saves the lines currently being processed in a temporary buffer (also known as mode space), and then processes the lines in the temporary buffer without directly modifying the original file (if you want to modify the original file, you can add corresponding parameters). After completion, it sends the processed lines to the screen.
grammar
Command line usagesed [option] 'Address location|sed Command of' filename Common options -e Make multiple edits -n Cancel default output -f appoint sed The file name of the script -r Using extended regular expressions -i Modify source file Common commands p Print line d Delete row i Insert on the previous line of the current line $i Insert on the last line a Insert on the next line of the current line $a Insert (append) on the next line of the last line c Replace entire line r read w Save as ! Reverse s Find replace g Replace whole line & Replace the contents of the reference lookup string in the string = Print line number
[root@server1 ~]# head -5 /etc/passwd > test.txt print document [root@server1 ~]# sed 'p' test.txt root:x:0:0:root:/root:/bin/bash root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/sbin/nologin bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin adm:x:3:4:adm:/var/adm:/sbin/nologin adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin [root@server1 ~]# sed -n 'p' test.txt #Cancel default output root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin Print 1-3 that 's ok [root@server1 ~]# sed -n '1,3p' test.txt root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin Delete row [root@server1 ~]# sed '1d' test.txt bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin [root@server1 ~]# sed -n '1d' test.txt #Cancel default output Single line insertion [root@server1 ~]# sed '1ihello' test.txt hello root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin Multiline insertion [root@server1 ~]# sed '1ihello\nworld' test.txt hello world root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin [root@server1 ~]# sed '1ihello\ > linux\ > world' test.txt #Insert multiple lines with newline Add [root@server1 ~]# sed '$ahello' test.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 adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin hello replace [root@server1 ~]# sed '1chello world' test.txt hello world 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 Match replacement #Matching syntax: / matching content/ [root@server1 ~]# sed '/bin/chello' test.txt #Find the line with bin and replace with hello hello hello hello hello hello read [root@server1 ~]# sed '$r /etc/hosts' test.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 adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin 127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 ::1 localhost localhost.localdomain localhost6 localhost6.localdomain6 192.168.226.40 admin 192.168.226.10 node1 192.168.226.20 node2 192.168.226.30 node3 Save as [root@server1 ~]# sed '1,3w 111' test.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 adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin [root@server1 ~]# cat 111 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@server1 ~]# sed -n '/root/w 111' test.txt #Save the row with root in 111 [root@server1 ~]# cat 111 root:x:0:0:root:/root:/bin/bash Reverse [root@server1 ~]# sed -n '1,3!p' test.txt adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin Find replace [root@server1 ~]# sed -n 's/root/ROOT/p' test.txt #Replace first by default ROOT:x:0:0:root:/root:/bin/bash [root@server1 ~]# sed -n 's/root/ROOT/gp' test.txt #Replace whole line ROOT:x:0:0:ROOT:/ROOT:/bin/bash Custom delimiter (generally used to find or replace content)/Separator (when) [root@server1 ~]# sed -n 's#/sbin/nologin#/bin/bash#gp' test.txt bin:x:1:1:bin:/bin:/bin/bash daemon:x:2:2:daemon:/sbin:/bin/bash adm:x:3:4:adm:/var/adm:/bin/bash lp:x:4:7:lp:/var/spool/lpd:/bin/bash Batch notes [root@server1 ~]# sed -n '1,3s/^/#/p' test.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 Remove all special characters from the file [root@server1 ~]# sed -n '1,3s/[/:]//gp' test.txt rootx00rootrootbinbash binx11binbinsbinnologin daemonx22daemonsbinsbinnologin Save the lookup string for reference in the replacement string [root@server1 ~]# sed -n '1,3s/\(root\)/\1 hello/gp' test.txt root hello:x:0:0:root hello:/root hello:/bin/bash [root@server1 ~]# sed -n '1,3s/root/& hello/gp' test.txt root hello:x:0:0:root hello:/root hello:/bin/bash Print line number [root@server1 ~]# sed -n '/bash$/= ' test.txt 1 Multieditor [root@server1 ~]# sed -ne '/bash$/= ' -ne '/bash$/p' test.txt 1 root:x:0:0:root:/root:/bin/bash Modify original document #If the - n option cannot be added, the file will be emptied #If you cannot add the p command, the file will have more lines to print [root@server1 ~]# sed -i 's/root/ROOT/g' test.txt [root@server1 ~]# cat test.txt ROOT:x:0:0:ROOT:/ROOT:/bin/bash bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologinOptions / commandsexplainusage-nCancel default output-eMake multiple editssed -ne '/nologin$/=' -ne '/nologin$/p' 1.txt-fspecify a filenameNo-rExtended regularity-iModify source fileCannot be used with the - i option and the p commandpPrint linesed -n '1,5p' a.txtdDelete rowsed -n '1d' a.txtiInsert on the previous line of the current linesed '1ihello\nworld' test.txt$iInsert on the last lineaInsert on the next line of the current linesed '5ahello' a.txt$aAddcReplace entire linesed '1,5chello world' a.txtrreadsed '3r /etc/hosts' 2.txtwSave assed '/root/w a.txt' 2.txt!Reversesed -n '1!p' 1.txtsFind replacesed -n 's/root/ROOT/p' 1.txtgReplace whole linesed -n 's/root/ROOT/gp' 1.txt&Replace the contents of the reference lookup string in the stringsed -n 's/root/#&/p' a.txt=Print line numbersed -n '/bash$/=' 1.txt case
- Remove all comments and blank lines when viewing the configuration file
Method 1 [root@server1 ~]# sed -e '/^#/d' -e '/^$/d' /etc/ssh/sshd_config HostKey /etc/ssh/ssh_host_rsa_key HostKey /etc/ssh/ssh_host_ecdsa_key HostKey /etc/ssh/ssh_host_ed25519_key SyslogFacility AUTHPRIV AuthorizedKeysFile .ssh/authorized_keys PasswordAuthentication yes ChallengeResponseAuthentication no GSSAPIAuthentication yes GSSAPICleanupCredentials no UsePAM yes X11Forwarding yes AcceptEnv LANG LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES AcceptEnv LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT AcceptEnv LC_IDENTIFICATION LC_ALL LANGUAGE AcceptEnv XMODIFIERS Subsystem sftp /usr/libexec/openssh/sftp-server Method 2 [root@server1 ~]# sed '/^#/d;/^$/d' /etc/ssh/sshd_config HostKey /etc/ssh/ssh_host_rsa_key HostKey /etc/ssh/ssh_host_ecdsa_key HostKey /etc/ssh/ssh_host_ed25519_key SyslogFacility AUTHPRIV AuthorizedKeysFile .ssh/authorized_keys PasswordAuthentication yes ChallengeResponseAuthentication no GSSAPIAuthentication yes GSSAPICleanupCredentials no UsePAM yes X11Forwarding yes AcceptEnv LANG LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES AcceptEnv LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT AcceptEnv LC_IDENTIFICATION LC_ALL LANGUAGE AcceptEnv XMODIFIERS Subsystem sftp /usr/libexec/openssh/sftp-server Method 3 [root@server1 ~]# sed -r '/^#|^$/d' /etc/ssh/sshd_config HostKey /etc/ssh/ssh_host_rsa_key HostKey /etc/ssh/ssh_host_ecdsa_key HostKey /etc/ssh/ssh_host_ed25519_key SyslogFacility AUTHPRIV AuthorizedKeysFile .ssh/authorized_keys PasswordAuthentication yes ChallengeResponseAuthentication no GSSAPIAuthentication yes GSSAPICleanupCredentials no UsePAM yes X11Forwarding yes AcceptEnv LANG LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES AcceptEnv LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT AcceptEnv LC_IDENTIFICATION LC_ALL LANGUAGE AcceptEnv XMODIFIERS Subsystem sftp /usr/libexec/openssh/sftp-server
- Get IP address
Method 1 [root@server1 ~]# ifconfig ens33 |sed '2!d' inet 192.168.226.10 netmask 255.255.255.0 broadcast 192.168.226.255 [root@server1 ~]# ifconfig ens33 |sed '2!d'|cut -d' ' -f10,13,16 192.168.226.10 255.255.255.0 192.168.226.255 Method 2 [root@server1 ~]# ifconfig ens33 |sed '2!d'|sed -n 's/ /\n/gp'|sed '/^$|[a-z]/d' inet 192.168.226.10 netmask 255.255.255.0 broadcast 192.168.226.255 [root@server1 ~]# ifconfig ens33 |sed '2!d'|sed -n 's/ /\n/gp'|sed -r '/^$|[a-z]/d' 192.168.226.10 255.255.255.0 192.168.226.255Used in scripts
- When writing sed script, you need to add its corresponding magic characters (command interpreter)
- Just write the content between '······'
- One command per line
- Note that there should be no spaces after the command
[root@server1 ~]# vim sed.sh #!/bin/sed -f 1,3d s/root/hello/g 2iworld [root@server1 ~]# cat test.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 adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin [root@server1 ~]# sed -f sed.sh test.txt adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin [root@server1 ~]# sed -f sed.sh -i test.txt #Modify original document [root@server1 ~]# cat test.txt adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
awk
summary
- Awk is a programming language. The basic function of awk language is to browse and extract information based on specified rules in files or strings. After awk extracts information, other text operations can be carried out.
- Complete awk scripts are often used to format information in text files.
- Generally, awk is based on the behavior of files. Awk receives each line of the file and then executes the corresponding command to process the text
- awk represents the first letter of the last names of the three authors, Alfred Aho, Brian Kernighan and Peter Weinberger.
- Gawk is an open source version of awk. Awk has been linked to gawk in linux system.
[root@server1 ~]# ll /bin/awk lrwxrwxrwx. 1 root root 4 7 June 24-17:32 /bin/awk -> gawk
Command mode usage
grammarawk option 'Regular, address status' file name Common options -F Specify a separator. You can specify one or more. The default separator is a space -v Define variables and assign values
-
’'command' is written in standard
Regular matching '/^root/' #Match start with root [root@server1 ~]# cat test.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 adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin [root@server1 ~]# awk -F: '/^root/' test.txt root:x:0:0:root:/root:/bin/bash Address location 'NR==1,NR==5' #Match lines 1-5 [root@server1 ~]# awk -F: 'NR==3' test.txt daemon:x:2:2:daemon:/sbin:/sbin/nologin Multiple awk Statement use;separate [root@server1 ~]# awk -F: 'NR==3' test.txt daemon 2 [root@server1 ~]# awk -F: 'NR==3' test.txt daemon 2 BEGIN END use 'BEGIN;;END' 'BEGIN;' ';END' [root@server1 ~]# awk -F: 'BEGIN;;END' /etc/passwd Login_shell Login_home ******** /bin/bash /root /sbin/nologin /bin /sbin/nologin /sbin /sbin/nologin /var/adm /sbin/nologin /var/spool/lpd /bin/sync /sbin /sbin/shutdown /sbin /sbin/halt /sbin /sbin/nologin /var/spool/mail /sbin/nologin /root /sbin/nologin /usr/games /sbin/nologin /var/ftp /sbin/nologin / /sbin/nologin / /sbin/nologin / /sbin/nologin / /sbin/nologin /var/empty/sshd /sbin/nologin /var/spool/postfix /sbin/nologin /usr/share/httpd /sbin/nologin /dev/null /sbin/nologin /var/lib/zabbix /bin/bash /home/cephu /sbin/nologin /etc/ntp ***********
Define input separator #Method 1: specify option - F [root@server1 ~]# awk -F: '' test.txt root /bin/bash bin /sbin/nologin daemon /sbin/nologin adm /sbin/nologin lp /sbin/nologin #Method 2: with the help of internal variable FS [root@server1 ~]# awk 'BEGIN;' test.txt root /bin/bash bin /sbin/nologin daemon /sbin/nologin adm /sbin/nologin lp /sbin/nologin Define output separator #default [root@server1 ~]# awk -F: '' test.txt root /bin/bash bin /sbin/nologin daemon /sbin/nologin adm /sbin/nologin lp /sbin/nologin #Method 1: specify between fields by writing between "" [root@server1 ~]# awk -F: '' test.txt root /bin/bash bin /sbin/nologin daemon /sbin/nologin adm /sbin/nologin lp /sbin/nologin #Method 2: with the help of internal variable OFS [root@server1 ~]# awk -F: 'BEGIN;' test.txt root /bin/bash bin /sbin/nologin daemon /sbin/nologin adm /sbin/nologin lp /sbin/nologin Define input record separator [root@server1 ~]# vim 1.txt 1 123^I456^I789$ 2 234 567$ 3 sdvffrrvf$ 4 ddfd sdg^Ifhh^Idd$ [root@server1 ~]# awk 'BEGIN;' 1.txt #The default line break is still in effect 123 456 789 234 567 sdvffrrvf ddfd sdg fhh dd Define output record separator [root@server1 ~]# awk '' 1.txt #default 123 456 789 234 567 sdvffrrvf ddfd sdg fhh dd [root@server1 ~]# awk 'BEGIN;' 1.txt 123 456 789 234 567 sdvffrrvf ddfd sdg fhh dd [root@server1 ~]#
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WorkflowTake awk -F: '' /etc/passwd as an example
- awk takes a line as input and assigns it to the internal variable $0. Each line is a record and ends with a newline character (RS)
- Each line is broken down into fields by the spacer colon (FS), and each field is stored in a numbered variable, starting at $1 and ending at $NF
- awk uses the print function to print fields. The printed fields are separated by spaces because there is a comma between $1 and $NF. Comma is special. It is mapped to another internal variable OFS. OFS defaults to space
- After awk processes one line, it will get another line from the file and store it in $0, overwrite the original content, and then separate the new string into fields and process it. This process will continue until all rows are processed
From lp The first line matches to line 10 [root@server1 ~]# awk '/^lp/,NR==10' /etc/passwd lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin sync:x:5:0:sync:/sbin:/bin/sync shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown halt:x:7:0:halt:/sbin:/sbin/halt mail:x:8:12:mail:/var/spool/mail:/sbin/nologin operator:x:11:0:operator:/root:/sbin/nologin Print 6-10 that 's ok [root@server1 ~]# awk 'NR>=6 && NR<=10' /etc/passwd sync:x:5:0:sync:/sbin:/bin/sync shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown halt:x:7:0:halt:/sbin:/sbin/halt mail:x:8:12:mail:/var/spool/mail:/sbin/nologin operator:x:11:0:operator:/root:/sbin/nologin Print 6-10 OK, to nologin Ending line [root@server1 ~]# awk 'NR>=6 && NR<=10 && /nologin$/' /etc/passwd mail:x:8:12:mail:/var/spool/mail:/sbin/nologin operator:x:11:0:operator:/root:/sbin/nologinFormat output printf
%s Character type %d value type - Indicates left alignment without default right alignment \n Line feed, printf The default line end does not wrap [root@server1 ~]# awk -F: '' /etc/passwd /bin/bash /root /sbin/nologin /bin /sbin/nologin /sbin /sbin/nologin /var/adm /sbin/nologin /var/spool/lpd /bin/sync /sbin /sbin/shutdown /sbin /sbin/halt /sbin /sbin/nologin /var/spool/mail /sbin/nologin /root /sbin/nologin /usr/games /sbin/nologin /var/ftp /sbin/nologin / /sbin/nologin / /sbin/nologin / /sbin/nologin / /sbin/nologin /var/empty/sshd /sbin/nologin /var/spool/postfix /sbin/nologin /usr/share/httpd /sbin/nologin /dev/null /sbin/nologin /var/lib/zabbix /bin/bash /home/cephu /sbin/nologin /etc/ntp
Script programming
Script execution[root@server1 ~]# vim awk.sh #!/bin/awk -f #Just write the content in '' BEGIN NR==1,NR==3 [root@server1 ~]# awk -f awk.sh /etc/passwd root /bin/bash bin /sbin/nologin daemon /sbin/nologinDefine variables
[root@server1 ~]# awk -v num=1 '' 1.txt 1 1 1 1 [root@server1 ~]# awk -v num=1 'BEGIN' 1Select execute
awk option 'Regular, address location}' file name awk option 'Regular, address location else}' file name awk option 'Regular, address location else if(Condition 2) else}' file name Case: print the of ordinary users UID And user name [root@server1 ~]# awk -F: '}' /etc/passwd cephu 1000 zhnagsan 1001 lisi 1002 [root@server1 ~]# Awk - F: ' else }' / etc/passwd root Non ordinary users bin Non ordinary users daemon Non ordinary users adm Non ordinary users lp Non ordinary users sync Non ordinary users shutdown Non ordinary users halt Non ordinary users mail Non ordinary users operator Non ordinary users games Non ordinary users ftp Non ordinary users nobody Non ordinary users systemd-network Non ordinary users dbus Non ordinary users polkitd Non ordinary users sshd Non ordinary users postfix Non ordinary users apache Non ordinary users tss Non ordinary users zabbix Non ordinary users cephu 1000 zhnagsan 1001 lisi 1002 [root@server1 ~]# Awk - F: ' else if ($3 = = 0) else ' / etc/passwd root administrators bin System user daemon System user adm System user lp System user sync System user shutdown System user halt System user mail System user operator System user games System user ftp System user nobody System user systemd-network System user dbus System user polkitd System user sshd System user postfix System user apache System user tss System user zabbix System user cephu Ordinary users ntp System user zhnagsan Ordinary users [root@server1 ~]# awk -F: ' else if($3==0) else}; End '/ etc/passwd 1 Administrators 21 System users 3 Ordinary usersCircular statement
Print 1,3,5,7,9 [root@server1 ~]# awk 'BEGIN}' 1 3 5 7 9 [root@server1 ~]# awk 'BEGIN}' 1 3 5 7 9arithmetic operation
Decimal operations can be performed + - * / %(model) **(power)Can be calculated [root@server1 ~]# awk 'BEGIN' 8 [root@server1 ~]# awk 'BEGIN' 0.666667case
Print ip address [root@server1 ~]# ifconfig ens33 |awk 'NR==2' 192.168.226.10 [root@server1 ~]# ifconfig ens33 |awk 'NR==2' 192.168.226.10 255.255.255.0 192.168.226.255 Statistics/etc/passwd Various types in shell Number of [root@server1 ~]# awk -F: ';END}' /etc/passwd /bin/sync 1 /bin/bash 4 /sbin/nologin 18 /sbin/halt 1 /sbin/shutdown 1