How do I replace all of the specific characters in a file? ---linux sed command (Text Edit command) (reprint)

Transferred from: http://blog.csdn.net/year_9/article/details/20318407

　　

Sed is a very good file processing tool, mainly in the Behavior unit processing, you can replace the data rows, delete, add, select and other specific work. (Total: Sed processing object is a file, how to deal with it?) Is it done on a line-by-row basis? Replace, delete: )
The SED command line format is:

sed [-nefri] ' command ' input text

Common options:

-I: Directly modify the contents of the read file instead of the screen output.

-N: Use Quiet (silent) mode. In the usage of general sed, all data from stdin is generally listed on the screen. However, if you add the-n parameter, only the line (or action) that is specially processed by SED is listed.

Common commands:
A: New, a can be followed by a string, and these strings will appear on a new line (the current next line) ~ such as: sed ' 1a end ' after the last line and then insert a line end (interview question)
C: Replace, C can be followed by strings, these strings can replace the line between N1,N2!
D: Delete, because it is deleted ah, so d usually do not pick up any boom;
I: Insert, I can be followed by the string, and these strings will appear on a new line (the current line);
S: Replace, can be directly replaced by work! Usually this s action can be paired with formal notation! For example 1,20s/old/new/g is!

P: Print, that is, print out a selected material. Normally p will work with parameter Sed-n ~

example: (Suppose we have a file named ab)
       Delete a row
     [[email protected] Ruby]# sed ' 1d ' ab              #删除第一行  
     [[email protected] ruby] # sed ' $d ' ab                #删除最后一行
     [email  protected] Ruby] # sed ' 1,2d ' ab             #删除第一行到第二行
     [[email protected] ruby] # sed ' 2, $d ' ab            #删除第二行到最后一行

Show a row
. [email protected] Ruby]# sed-n ' 1p ' ab #显示第一行
[[email protected] ruby] # sed-n ' $p ' ab #显示最后一行
[[email protected] ruby] # sed-n ' 1,2p ' ab #显示第一行到第二行
[[email protected] ruby] # sed-n ' 2, $p ' AB #显示第二行到最后一行

Querying using a pattern
[[email protected] ruby] # sed-n '/ruby/p ' ab #查询包括关键字ruby所在所有行
[[email protected] ruby] # sed-n '/\$/p ' AB #查询包括关键字 $ where all lines, using backslashes \ Shielding special meaning

Add one or more lines of string
[email protected] ruby]# Cat AB
Hello!
Ruby is me,welcome to my blog.
End
[[email protected] ruby]# sed ' 1a drink tea ' ab#第一行后增加字符串 "Drink Tea"
Hello!
Drink tea
Ruby is me,welcome to my blog.
End
[[email protected] ruby]# sed ' 1,3a drink tea ' ab #第一行到第三行后增加字符串 "Drink Tea"
     hello!
     drink Tea
     Ruby is me,welcome to my blog.
     drink Tea
     end
     drink Tea
     [[email protected] ruby] # sed ' 1a drink tea\nor Coffee ' ab   #第一行后增加多行, use line break \ n
     hello!
     drink Tea
     or coffee
     Ruby is Me , Welcome to my blog.
     End

Instead of one or more lines
     [[email protected] ruby] # sed ' 1c Hi ' ab& nbsp;               #第一行代替为Hi
     Hi
     Ruby is Me, Welcome to my blog.
     End
     [[email protected] Ruby] # sed ' 1,2c Hi ' ab              #第一行到第二行代替为Hi
     Hi
     End

replace part of a row
format: SED "s/the string to replace /new string /g"    (the string to be replaced can be used with regular expressions)
     [[email protected] Ruby] # sed-n '/ruby/p ' ab | Sed ' s/ruby/bird/g '     #替换ruby为bird
  [[email protected] ruby] # sed-n '/ruby/p ' ab | Sed ' s/ruby//g '         #删除ruby

Insert
[[email protected] ruby] # sed-i ' $a bye ' ab #在文件ab中最后一行直接输入 "Bye"
[email protected] ruby]# Cat AB
Hello!
Ruby is me,welcome to my blog.
End
Bye

Summarize:

1, insert a row of data in the last line

2, find the line containing the MO string, and display it (generally with grep, but SED can also)

3. Delete a string (all of the files)

4. Find more specific characters in the file and replace them!

SED handles file objects, line by row!

You can delete a file by deleting the row: sed-i ' XXd ' filename

Delete specific characters: Sed-i ' s/string//g '

Replace Replace line:

To replace a specific character:

"Add" adds a row:

"Choose" sed-n ' xxx/p ' filename

How do I replace all of the specific characters in a file? ---linux sed command (Text Edit command) (reprint)