The SED of shell programming

First, sed (Stream Editor)

1, positioning line:
Sed-n ' 12,~3p ' pass #从第12行开始 until the next 3 multiples line (12-15 lines)
Sed-n ' 12,+4p ' pass #从第12行开始, 4 consecutive lines (12-16 lines)
Sed-n ' 12~3p ' pass #从第12行开始, interval 3 lines output once (12,15,18,21 ...)
Sed-n ', $p ' pass #从第10行至结尾
Sed-n ' 4!p ' pass #除去第4行

2. Regular: '/regular type/'
Sed-n '/root/p '/etc/passwd
Sed-n '/^root/p '/etc/passwd
Sed-n '/bash$/p '/etc/passwd
Sed-n '/ro.t/p '/etc/passwd
Sed-n '/ro*/p '/etc/passwd
Sed-n '/[abc]/p '/etc/passwd
Sed-n '/[a-z]/p '/etc/passwd
Sed-n '/[^abc]/p '/etc/passwd
Sed-n '/^[^abc]/p '/etc/passwd
Sed-n '/\<root/p '/etc/passwd
Sed-n '/root\>/p '/etc/passwd

3. Extended Regular:
Sed-n '/root\|yerik/p '/etc/passwd #拓展正则需要转义
Sed-nr '/root|yerik/p '/etc/passwd #加-R parameter support extended regular
Sed-nr '/ro (ot|ye) rik/p '/etc/passwd #匹配rootrik和royerik单词
Sed-nr '/ro?t/p '/etc/passwd # match 0-1 leading characters
Sed-nr '/ro+t/p '/etc/passwd #匹配1-N Secondary leading character
Sed-nr '/ro{2}t/p '/etc/passwd #匹配2次前导字符
Sed-nr '/ro{2,}t/p '/etc/passwd #匹配多于2次前导字符
Sed-nr '/ro{2,4}t/p '/etc/passwd #匹配2-4 leading characters
Sed-nr '/(Root) */p '/etc/passwd #匹配0-n secondary leading word

4. Sed edit (insert, delete, replace for row)
Sed '/root/a admin '/etc/passwd #在root行后追加一个admin行
Sed '/root/i admin '/etc/passwd #在root行前插入一个admin
Sed '/root/c admin '/etc/passwd #将root行替换为admin
Sed '/root/d '/etc/passwd #删除含有root的行

S replacement
Sed-n ' s/root/admin/p '/etc/passwd
Sed-n ' s/root/admin/2p '/etc/passwd #在每行的第2个root作替换
Sed-n ' S/ROOT/ADMIN/GP '/etc/passwd
Sed-n ' 1,10 s/root/admin/gp '/etc/passwd
Sed-n ' s/root/aaa&bbb/2p '/etc/passwd #将root替换成AAArootBBB,& as a reverse reference instead of the previous match
Sed-ne ' s/root/aaa&bbb/'-ne ' s/bash/aaa&bbb/p '/etc/passwd #-e Connect multiple commands to replace root or bash lines
Sed-n ' s/root/aaa&bbb/;s/bash/aaa&bbb/p '/etc/passwd #与上命令功能相同
Sed-nr ' s/(Root) (. *) (bash)/\3\2\1/p '/etc/passwd #将root与bash位置替换, two tag replacements
or Sed-n ' s/\ (root\) \ (. *\) \ (bash\)/\3\2\1/p '/etc/passwd
Bash:x:0:0:root:/root:/bin/root

Y Replace
echo "Sorry" |sed ' y/ory/abc/' #一一对应替换 (SABBC)

6. Sed mode space and hold space
H: Mode----> Hold
H: Mode--->> hold
X: Mode <---> Hold
G: Maintain----> Mode
G: Maintain--->> mode

For example:
111
222
333
444
# sed ' 1h;2,3h;4g '

cmd         mode      hold
111          111     \ n
1h           111     111
----------->111
222          222     111
2,3h        222     111\n222 
----------->222
333          333     111\n222
2,3h        333      111\n222\n333
----------->333
444         444     111\n222\n333
4g          444\n111\ n222\n333
----------->444\n111\n222\n333

1-10
11-22
22-33
11-22
34-end

7. Special use of SED
Sed-n '/root/w a.txt ' #将匹配行输出到文件
Sed '/root/r abc.txt '/etc/passwd #把abc. txt file contents after reading into the root matching line
Sed-n '/root/w a.txt '
Sed-n '/root/{=;p} '/etc/passwd #打印行号和匹配root的行
Sed-n '/root/{n;d} '/etc/passwd #将匹配root行的下一行删除
Sed-n '/root/{n;d} '/etc/passwd #将匹配root行和下一行都删除
Sed ' 22{h;d};23,33{h;d};44g ' pass

8. Sed script Writing method
<1> read-in commands from a file
Sed-f sed.sh
sed.sh File Contents:
s/root/yerik/p
s/bash/csh/p

<2> run the script directly./sed.sh/etc/passwd
#!/bib/sed-f
s/root/yerik/p
s/bash/csh/p

###################################
Ii. sed Exercises

1. Delete the first character of each line of the file.
Sed-n ' S/^.//GP '/etc/passwd
Sed-nr ' s/(.) (. *)/\2/p '/etc/passwd
2. Delete the second character of each line of the file.
Sed-nr ' s/(.) (.) (. *)/\1\3/p '/etc/passwd

3. Delete the last character of each line of the file.
Sed-nr ' s/.$//p '/etc/passwd
Sed-nr ' s/(. *) (.) /\1/p '/etc/passwd

4. Delete the second-to-last character of each line of the file.
Sed-nr ' s/(. *) (.) (.) /\1\3/p '/etc/passwd

5. Delete the second word in each line of the file.
Sed-nr ' s/([^a-z]*) ([a-z]+) ([^a-z]+] ([a-z]+) (. *)/\1\2\3\5/p '/etc/passwd

6. Delete the second-to-last word in each line of a file.
Sed-nr ' s/(. *) ([^a-z]+) ([a-z]+) ([^a-z]+] ([a-z]+) ([^a-z]*]/\1\2\4\5\6/p '/etc/samba/smb.conf

7. Delete the last word in each line of the file.
Sed-nr ' s/(. *) ([^a-z]+) ([a-z]+) ([^a-z]*]/\1\2\4/p '/etc/samba/smb.conf

8, swaps the first character and the second character of each line.
Sed-nr ' s/(.) (.) (. *)/\2\1\3/p '/etc/passwd

9, swap the first word and the second word for each line.
Sed-nr ' s/([^a-z]*) ([a-z]+) ([^a-z]+] ([a-z]+) (. *)/\1\4\3\2\5/p '/etc/samba/smb.conf

10, swap the first word and the last word of each line.
Sed-nr ' s/([^a-z]*) ([a-z]+) ([^a-z]+] ([a-z]+) (. *)/\1\4\3\2\5/p '/etc/passwd

11, delete all the numbers in a file.
Sed ' s/[0-9]*//g '/etc/passwd

12, remove all spaces at the beginning of each line.
Sed-n ' s/^\ *//p '/etc/samba/smb.conf
Sed-nr ' s/(*) (. *)/\2/p ' TESTP

13, replace any spaces that appear in the file with tabs.
Sed-n ' s/\/\t/gp ' pass

14, enclose all uppercase letters in parentheses ().
Sed-nr ' s/([A-z])/(&)/GP ' TESTP
Sed-n ' s/[a-z]/(&)/GP ' TESTP

15, print 3 times per line.
Sed ' p;p ' pass

16, interlace Delete.
Sed-n ' 1~2p ' Pass

17, copy the file from line 22nd to line 33rd to the end of line 44th.
Sed ' 1,21h;22h;23,33h;44g ' pass

18, move the file from line 22nd to line 33rd to the end of line 44th.
Sed ' 22{h;d};23,33{h;d};44g ' pass

19, only the first word of each line is displayed.
Sed-nr ' s/([^a-z]*) ([a-z]+) ([^a-z]+] (. *)/\2/p '/etc/passwd

20, print the first word and the third word of each line.
Sed-nr ' s/([^a-z]*) ([a-z]+] ([^a-z]+) ([a-z]+] ([^a-z]+) ([a-z]+] (. *)/\2--\4/p '/etc/passwd

21, change the format of the date format mm/yy/dd to MM;YY;DD
Date +%m/%y/%d |sed-n ' s#/#; #gp '

22, Reverse output
Cat A.txt
Abc
Def
Xyz
The output style becomes
Xyz
Def
Abc

The SED of shell programming