Shell programming editor sed of Three Musketeers
Introduction to a sed tool
Sed is the abbreviation of Stream Editor, referred to as stream editor; used to process files.
The working principle of sed:
firstly, sed reads the content of a line in the file, saves it in a temporary buffer area (also known as pattern space), then processes the line in the temporary buffer according to requirements, and sends the line to the screen after completion on.
note:
Since sed stores each line in a temporary buffer and edits the copy, it will not directly modify the original file.
Sed is mainly used to automatically edit one or more files; it simplifies the repeated operation of files, and filters and converts files. operating
Two sed syntax format
sed [-option]'keyword' filename
2.1 Common options
| Options | meaning |
|---|---|
| -e | Make multiple (multiple) edits |
| -n | Cancel the default output |
| -r | Use extended regular expressions |
| -i | Modify the source file (use with caution) |
| -f | Specify the file name of the sed script |
2.2 Common keywords
All of the following keywords (action) should be in single quotes in
| Keyword | meaning |
|---|---|
| ‘p’ | |
| ‘i’ | Insert content before the specified line |
| ‘a’ | Insert content after the specified line |
| ‘c’ | Replace all contents of the specified line |
| ‘d’ | Delete specified line |
2.3 Other keywords
| Options | meaning | Explanation |
|---|---|---|
| r | Read content from another file | |
| w | Save content as | |
| & | Save the search string for reference in the replacement string | the same as |
| = | Print line number | |
| ！ | Apply the command to all lines except the selected line, after the line number | |
| q | drop out |
2.4 sed combined with regular expressions
| Regular | Description | Remarks |
|---|---|---|
| /key/ | Query rows containing keywords | sed -n ‘/root/p’ 1.txt |
| /key1/,/key2/ | Matches lines that contain between two keywords | sed -n ‘/^adm/,/^mysql/p’ 1.txt |
| /key/,x | From the line where the keyword matches to the line between line x of the file (including the line where the keyword is located) | sed -n ‘/^ftp/,7p’ |
| x,/key/ | The line starting from line x of the file to the line matching the keyword | |
| x, y! | Does not contain rows x to y | |
| /key/! | Lines that do not include keywords | sed -n ‘/bash$/!p’ 1.txt |
Three sed usage examples
3.1 Experimental text
# vim cj.txt
root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/bin:/sbin/nologin
daemon:x:2:2:daemon:/sbin:/sbin/nologin
adm:x:3:4:adm:/var/adm:/sbin/nologin
lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
298374837483
172.16.0.254
10.1.1.1
3.2 Adding, deleting, modifying and checking operations
3.2.1 Print file content
'p' print
[root@server ~]# sed '' cj.txt 对文件什么都不做
[root@server ~]# sed -n 'p' cj.txt 打印每一行，并取消默认输出
[root@server ~]# sed -n '1p' cj.txt 打印第1行
[root@server ~]# sed -n '2p' cj.txt 打印第2行
[root@server ~]# sed -n '1,5p' cj.txt 打印1到5行
[root@server ~]# sed -n '$p' cj.txt 打印最后1行
3.2.2 Add file content
'i' insert content before the specified line'a' insert content
after the specified line
[root@server ~]# sed '$a666' cj.txt 文件最后一行下面增加内容
[root@server ~]# sed 'a6666' cj.txt 文件每行下面增加内容
[root@server ~]# sed '5a666' cj.txt 文件第5行下面增加内容
[root@server ~]# sed '$i666' cj.txt 文件最后一行上一行增加内容
[root@server ~]# sed 'i6666' cj.txt 文件每行上一行增加内容
[root@server ~]# sed '6i666' cj.txt 文件第6行上一行增加内容
[root@server ~]# sed '/^uucp/ihello' 以uucp开头行的上一行插入内容
3.2.3 Delete file content
'd' delete the specified line
[root@server ~]# sed '1d' cj.txt 删除文件第1行
[root@server ~]# sed '1,5d' cj.txt 删除文件1到5行
[root@server ~]# sed '$d' cj.txt 删除文件最后一行
3.2.4 Modify file content
'c' replace all contents of the specified line
[root@server ~]# sed '5chello world' cj.txt 替换文件第5行内容
[root@server ~]# sed 'chello world' cj.txt 替换文件所有内容
[root@server ~]# sed '1,5chello world' cj.txt 替换文件1到5号内容为hello world
[root@server ~]# sed '/^user01/c888' cj.txt 替换以user01开头的行
3.3 File search and replacement operation★★★
Sed file options 's / search / content replacement / acts' in need of treatment: syntax
example: sed -i 's /': '/' '/ g' /opt/cj.txt the colon replaced with spaces
wherein , S means search; slash/ means separator, you can define it yourself, and change to @ or # also applies; the action is generally to print p and replace g globally (part)
[root@server ~]# sed -n 's/root/ROOT/p' 1.txt
[root@server ~]# sed -n 's/root/ROOT/gp' 1.txt
[root@server ~]# sed -n 's/^#//gp' 1.txt
[root@server ~]# sed -n 's@/sbin/nologin@itcast@gp' cj.txt
[root@server ~]# sed -n 's/\/sbin\/nologin/itcast/gp' cj.txt
[root@server ~]# sed -n '10s#/sbin/nologin#itcast#p' cj.txt
uucp:x:10:14:uucp:/var/spool/uucp:itcast
[root@server ~]# sed -n 's@/sbin/nologin@itcastheima@p' 2.txt
注意：搜索替换中的分隔符可以自己指定
[root@server ~]# sed -n '1,5s/^/#/p' a.txt 注释掉文件的1-5行内容
#root:x:0:0:root:/root:/bin/bash
#bin:x:1:1:bin:/bin:/sbin/nologin
#daemon:x:2:2:daemon:/sbin:/sbin/nologin
#adm:x:3:4:adm:/var/adm:/sbin/nologin
#lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
3.4 Operation cases of other keywords
r 从文件中读取输入行
w 将所选的行写入文件
[root@server ~]# sed '3r /etc/hosts' 2.txt
[root@server ~]# sed '$r /etc/hosts' 2.txt
[root@server ~]# sed '/root/w a.txt' 2.txt
[root@server ~]# sed '/[0-9]{4}/w a.txt' 2.txt
[root@server ~]# sed -r '/([0-9]{1,3}\.){3}[0-9]{1,3}/w b.txt' 2.txt
! 对所选行以外的所有行应用命令，放到行数之后
[root@server ~]# sed -n '1!p' 1.txt
[root@server ~]# sed -n '4p' 1.txt
[root@server ~]# sed -n '4!p' 1.txt
[root@server ~]# cat -n 1.txt
[root@server ~]# sed -n '1,17p' 1.txt
[root@server ~]# sed -n '1,17!p' 1.txt
& 保存查找串以便在替换串中引用 \(\)
[root@server ~]# sed -n '/root/p' a.txt
root:x:0:0:root:/root:/bin/bash
[root@server ~]# sed -n 's/root/#&/p' a.txt
#root:x:0:0:root:/root:/bin/bash
# sed -n 's/^root/#&/p' passwd 注释掉以root开头的行
# sed -n -r 's/^root|^stu/#&/p' /etc/passwd 注释掉以root开头或者以stu开头的行
# sed -n '1,5s/^[a-z].*/#&/p' passwd 注释掉1~5行中以任意小写字母开头的行
# sed -n '1,5s/^/#/p' /etc/passwd 注释1~5行
或者
sed -n '1,5s/^/#/p' passwd 以空开头的加上#
sed -n '1,5s/^#//p' passwd 以#开头的替换成空
[root@server ~]# sed -n '/^root/p' 1.txt
[root@server ~]# sed -n 's/^root/#&/p' 1.txt
[root@server ~]# sed -n 's/\(^root\)/#\1/p' 1.txt
[root@server ~]# sed -nr '/^root|^stu/p' 1.txt
[root@server ~]# sed -nr 's/^root|^stu/#&/p' 1.txt
= 打印行号
# sed -n '/bash$/=' passwd 打印以bash结尾的行的行号
# sed -ne '/root/=' -ne '/root/p' passwd
# sed -n '/nologin$/=;/nologin$/p' 1.txt
# sed -ne '/nologin$/=' -ne '/nologin$/p' 1.txt
q 退出
# sed '5q' 1.txt
# sed '/mail/q' 1.txt
# sed -r '/^yunwei|^mail/q' 1.txt
[root@server ~]# sed -n '/bash$/p;10q' 1.txt
ROOT:x:0:0:root:/root:/bin/bash
综合运用：
[root@server ~]# sed -n '1,5s/^/#&/p' 1.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@server ~]# sed -n '1,5s/\(^\)/#\1/p' 1.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
3.5 Operation cases of remaining common options
-e 多项编辑
-r 扩展正则
-i 修改原文件
[root@server ~]# sed -ne '/root/p' 1.txt -ne '/root/='
root:x:0:0:root:/root:/bin/bash
1
[root@server ~]# sed -ne '/root/=' -ne '/root/p' 1.txt
1
root:x:0:0:root:/root:/bin/bash
在1.txt文件中的第5行的前面插入“hello world”;在1.txt文件的第8行下面插入“哈哈哈哈”
[root@server ~]# sed -e '5ihello world' -e '8a哈哈哈哈哈' 1.txt -e '5=;8='
sed -n '1,5p' 1.txt
sed -ne '1p' -ne '5p' 1.txt
sed -ne '1p;5p' 1.txt
过滤vsftpd.conf文件中以#开头和空行：
[root@server ~]# grep -Ev '^#|^$' /etc/vsftpd/vsftpd.conf
[root@server ~]# sed -e '/^#/d' -e '/^$/d' /etc/vsftpd/vsftpd.conf
[root@server ~]# sed '/^#/d;/^$/d' /etc/vsftpd/vsftpd.conf
[root@server ~]# sed -r '/^#|^$/d' /etc/vsftpd/vsftpd.conf
过滤smb.conf文件中生效的行：
# sed -e '/^#/d' -e '/^;/d' -e '/^$/d' -e '/^\t$/d' -e '/^\t#/d' smb.conf
# sed -r '/^(#|$|;|\t#|\t$)/d' smb.conf
# sed -e '/^#/d' -e '/^;/d' -e '/^$/d' -e '/^\t$/d' -e '/^\t#/' smb.conf
[root@server ~]# grep '^[^a-z]' 1.txt
[root@server ~]# sed -n '/^[^a-z]/p' 1.txt
过滤出文件中的IP地址：
[root@server ~]# grep -E '([0-9]{1,3}\.){3}[0-9]{1,3}' 1.txt
192.168.0.254
[root@server ~]# sed -nr '/([0-9]{1,3}\.){3}[0-9]{1,3}/p' 1.txt
192.168.0.254
[root@server ~]# grep -o -E '([0-9]{1,3}\.){3}[0-9]{1,3}' 2.txt
10.1.1.1
10.1.1.255
255.255.255.0
[root@server ~]# sed -nr '/([0-9]{1,3}\.){3}[0-9]{1,3}/p' 2.txt
10.1.1.1
10.1.1.255
255.255.255.0
过滤出ifcfg-eth0文件中的IP、子网掩码、广播地址
[root@server shell06]# grep -Eo '([0-9]{1,3}\.){3}[0-9]{1,3}' ifcfg-eth0
10.1.1.1
255.255.255.0
10.1.1.254
[root@server shell06]# sed -nr '/([0-9]{1,3}\.){3}[0-9]{1,3}/p' ifcfg-eth0|cut -d'=' -f2
10.1.1.1
255.255.255.0
10.1.1.254
[root@server shell06]# sed -nr '/([0-9]{1,3}\.){3}[0-9]{1,3}/p' ifcfg-eth0|sed -n 's/[A-Z=]//gp'
10.1.1.1
255.255.255.0
10.1.1.254
[root@server shell06]# ifconfig eth0|sed -n '2p'|sed -n 's/[:a-Z]//gp'|sed -n 's/ /\n/gp'|sed '/^$/d'
10.1.1.1
10.1.1.255
255.255.255.0
[root@server shell06]# ifconfig | sed -nr '/([0-9]{1,3}\.)[0-9]{1,3}/p' | head -1|sed -r 's/([a-z:]|[A-Z/t])//g'|sed 's/ /\n/g'|sed '/^$/d'
[root@server shell06]# ifconfig eth0|sed -n '2p'|sed -n 's/.*addr:\(.*\) Bcast:\(.*\) Mask:\(.*\)/\1\n\2\n\3/p'
10.1.1.1
10.1.1.255
255.255.255.0
-i 选项 直接修改原文件
# sed -i 's/root/ROOT/;s/stu/STU/' 11.txt
# sed -i '17{s/YUNWEI/yunwei/;s#/bin/bash#/sbin/nologin#}' 1.txt
# sed -i '1,5s/^/#&/' a.txt
注意：
-ni 不要一起使用
p命令 不要再使用-i时使用