Linux sed for personal use

First, SED

1. Replace the nth (if any) of each line with a match

sed "s/regexpr/anyword/${n}" filename

Cat filename
111111111111111111
222222222222222222
333333333333333333
444444444444444444
Example
Sed "s/4/four/8" filename
111111111111111111
222222222222222222
333333333333333333
4.,444,444,444,444,44e,+17

2. Replace the first match of each line

[ - ]

CODE:

Sed ' s/regexpr/anyword/' filename
Sed ' s/regexpr/anyword/1 ' filename

Example:

QUOTE:

Cat filename
1234567890 2345678901
3456789012 4567890123
Sed ' s/5/five/' filename
1,234,567,890 2345678901
3,456,789,012 4567890123

3. Line number Processing

1> Add a line number to a file

CODE:

sed = filename|sed ' n;s/\n/:/'
Cat filename
111111111111111111
222222222222222222
333333333333333333
444444444444444444

Example

[ - ]

CODE:

sed = filename|sed ' n;s/\n/:/' filename
1:1.,111,111,111,111,11e,+17
2:2.,222,222,222,222,22e,+17
3:3.,333,333,333,333,33e,+17
4:4.,444,444,444,444,44e,+17

2> Line numbers only for body lines in a file

[ - ]

CODE:

Cat filename
111111111111111111
< BR style= "Background-color:inherit;" >222222222222222222
333333333333333333

444444444444444444

sed/./= a|sed '/./n;s/\n/:/' filename
1:111111111111111111

3:222222222222222222
4:333333333333333333

6:444444444444444444

3>. String rollover

[ - ]

CODE:

Echo 1234567890|sed '/\n/! G;s/\ (. \) \ (. *\n\)/&\2\1/;//d;s/.//'
0987654321

#########################################################

#########################################################

Four. Selective output

1. Print document odd lines (interlaced output)

[ - ]

CODE:

Sed ' n;d '
Sed ' x;$! N;x '
Sed-n ' P;n '

1
3
5
7

2. Print even lines (interlaced output)

[ - ]

CODE:

Sed-n ' N;p '
Sed ' 1d;n;d; '
2
4
6
8

3. Delete consecutive duplicate rows (be careful when using the pattern space file too Large)

[ - ]

CODE:

Sed ' $! N /^\ (. *\) \n\1$/! P D
#使用 $! N Beware of memory overflow

Example

[ - ]

CODE:

Cat file
111111111111111111
222222222222222222
222222222222222222
333333333333333333
444444444444444444
444444444444444444
444444444444444444

sed" $! N /^\ (. *\) \n\1$/! P D ' filename
111111111111111111
333333333333333333
444444444444444444

4. Merging the upper and lower lines and separating them with spaces

[ - ]

CODE:

Cat file
1234567890
0987654321
After executing the command
1234567890 0987654321

5. Merge lines that end with the \ sign with the following line and separate them with spaces (punctuation breaks)

[ - ]

CODE:

Cat filename
1 111111111111111111\
2 222222222222222222
3 333333333333333333\
4 444444444444444444

SED-E: A-e '/\\$/n; s/\\\n//; Ta ' filename
1 111111111111111111 2 222222222222222222
3 333333333333333333 4 444444444444444444

6. Splicing Lines by keywords
If a row starts with =, merge to the previous line and replace = blank

[ - ]

CODE:

Cat file
111111111111111111
222222222222222222
=333333333333333333
444444444444444444

SED-E: A-e ' $! n;s/\n=//;ta '-e ' p;d ' filename
111111111111111111
222222222222222222 333333333333333333
444444444444444444

7. Output the next line that matches the row

[ - ]

CODE:

Cat filename
1 111111111111111111
2 222222222222222222
3 333333333333333333
4 444444444444444444

Sed-n '/^3/{n;p;} ' filename
4 444444444444444444

8. Displays the line number of the matching row and outputs the upstream, matching row, and downstream of the matching row

Sed-n-E '/regexpr/{=;x;1!p;g;$! n;p;d;} ' -E H
Example

[ - ]

CODE:

Cat filename
1 111111111111111111
2 222222222222222222
3 333333333333333333
4 444444444444444444

sed-n-E '/^3/{=;x;1!p;g;$! n;p;d;} ' -E h  filename
3                                        # Line number of the matching line
2 222222222222222222   #上一行
3 333333333333333333   #匹配行
4 444444444444444444   #下一行

9. Delete the keyword matching line in a flag area in the document

Delete a row in a document that contains MyWord from being to end in a block

[ - ]

CODE:

Sed '/^begin/,/^end/{/myword/d;} ' filename

QUOTE:

Cat filename
MyWord
Begin
MyWord
number!
MyWord
number!
MyWord
number!
MyWord
number!
End
MyWord
number!

Test

QUOTE:

MyWord
Begin
number!
number!
number!
number!
End
MyWord
number!

Five. String parsing

1. Parse two substrings from a string (first 2 characters and 9 chars)

[ - ]

CODE:

echo "Welovechinaunix" |sed-e ' h;s/\ (.. \). */\1/;x;s/.*\ (. \{9\}\) $/\1/;x; g;s/\n//'
We Chinaunix

2. Decomposition Date string

[ - ]

CODE:

Echo 20030922|sed ' s/\ (..... \) \ (.. \)\(.. \)/\1 \2 \3/' |read year Month Day
echo $year $month $day
2003 09 22

######################################################################################

########################################################################################

Cat file
1 192.148.99.253 [17/jun/2003:11:25:44/sc 
2 192.148.99.253 [17/jun/2003:11:18:21/si 
1 192.148.99.253 [17/jun/ 2003:11:20:34/SP&NBSP;
2 192.148.99.253 [17/JUN/2003:11:18:13/AP&NBSP;
1 192.148.99.253 [17/jun/2003:11:17:30/hou/ 
1 192.93.108.187 [17/jun/ 2003:14:49:14/SC&NBSP;
3 192.93.108.187 [17/JUN/2003:14:39:11/SI&NBSP;
5 192.68.82.78   [05/jun/2003:00:05:45/hou/ 
9 192.68.82.78   &NBSP;[05/JUN/2003:00:05:45/SS&NBSP;
4 192.228.210.10 [16/jun/ 2003:09:29:30/hou/

D=6
To fetch the sixth line of the file, the
Single quotation marks

[ - ]

CODE:

Sed-n ' "$d" '/P ' file
1 192.93.108.187 [17/JUN/2003:14:49:14/SC

Double quotes

[ - ]

CODE:

Sed-n "$d" p file or sed-n "${d}p" file
1 192.93.108.187 [17/JUN/2003:14:49:14/SC

The result is exactly the same.
and
Take the 1th to 6th line of the file:
Single quotes:

[ - ]

CODE:

Sed-n ' 1, ' "$d" ' p ' file
1 192.148.99.253 [17/JUN/2003:11:25:44/SC
2 192.148.99.253 [17/jun/2003:11:18:21/si
1 192.148.99.253 [17/jun/2003:11:20:34/sp
2 192.148.99.253 [17/jun/2003:11:18:13/ap
1 192.148.99.253 [17/jun/2003:11:17:30/hou/
1 192.93.108.187 [17/JUN/2003:14:49:14/SC

Linux sed for personal use