Self-study Linux instruction analysis-sed

Self-study Linux instruction analysis-sed

1 · command format

sed [-NEFRI]/Input text/' command ' file

2 · Command parameters

-N cancels the default output

-I changes the content of the output

-E makes multiple edits, which are used when multiple SED commands are applied to the input rows. Action editing of SED directly in command-column mode

-f Specifies the file name of the SED script. Directly write the SED action in a file, and-f filename to perform the SED action within the filename

The action of the-R SED supports the syntax of the extended regular expression. (presets are the underlying regular expression syntax

Common directives:
A: New, a can be followed by a string, and these strings will appear on a new line (the next line)
C: Replace, C can be followed by a string, these strings can replace the line between N1,N2
D: Delete, because it is deleted, so D usually does not pick up any content after
I: Insert, I can be followed by a string, and these strings will appear on a new line (the current line)
P: Printing, that is, printing out a selected material. Usually P is used in conjunction with the parameter sed-n
S: Replace, can be directly to replace the work. Usually this s action can be paired with regular expressions. such as 1,20s/old/new/g

3. Command function

(Delete, modify, replace, add) One of the core commands, (Taoyuan three jieyi, Dick)

4. Command Fan List

Real one: The known file Test.txt content is:

Test

Liyao

Oldboy

Please give a command that does not contain a Oldboy string when printing test.txt content

Command one: sed/oldboy/d test.txt

[email protected] tmp]# cat Test.txt
Test
Liyao
Oldboy
[Email protected] tmp]# sed/oldboy/d test.txt
Test
Liyao

Command two: Sed-n/oldboy/p test.txt only show Oldboy

[email protected] tmp]# cat Test.txt
Test
Liyao
Oldboy

[Email protected] tmp]# sed-n/oldboy/p test.txt
Oldboy

[Email protected] ~]# sed-n 20,30p ett.txt

20

。。。

30

Replace all strings that contain oldboylinux in files that end with extension ett.txt in the/directory and their subdirectories with Dboywindow

[Email protected] ~]# echo oldboylinux >ett.txt

[email protected] ~]# cat Ett.txt

• Oldboylinux

[email protected] ~]# CP ett.txt/etc/

[email protected] ~]# CP ett.txt/opt/

[[Email protected] ~]# sed s#oldboylinux#oldboywindows#g ett.txt This bar just changed the output, but the source file has not changed

(s = edit Replace

g = Replace All)

• Oldboywindows

[email protected] ~]# cat Ett.txt

Oldboylinux

[[email protected] ~]# sed-i s#oldboylinux#oldboywindows#g ett.txt (sed–i means changing content)

[email protected] ~]# cat Ett.txt

• Oldboywindows

[[email protected] ~]# Find/-type f-name "Ett.txt" Find the original file

/etc/ett.txt

/root/ett.txt

/opt/ett.txt

[[email protected] ~]# Find/-type f-name "Ett.txt" |xargs sed-i s#oldboylinux#oldboywindows#g Answer

[Email protected] ~]# Cat/etc/ett.txt

• Oldboywindows

[Email protected] ~]# Cat/opt/ett.txt

Oldboywindows

[[email protected] ~]# Find/-type f-name "Ett.txt" |xargs cat via Pipe | Progressive processing, instruction cat (view content)

• Oldboywindows
• Oldboywindows
• Oldboywindows

[[email protected] ~]# Find/-type f-name "Ett.txt" |xargs ls via pipe | Progressive processing, command LS (view list)

/etc/ett.txt/opt/ett.txt/root/ett.txt

Self-study Linux instruction analysis-sed