Linux grep command and sed command __linux

The principle of doing things enough, or endless, simple use of the grep command and sed command.

1, grep

Grammar:

grep pattern filename

Pattern (search for strings, numbers, etc., you can also use positive expressions, wildcard characters, and so on)

FileName (File/directory or.)

Parameters

Parameters	function
- I.	Ignore Case
-W	Whole Word match
-r/r	recursively match files in a folder
- N	Show Line Numbers
-C	Show number of matching rows
-V	Show lines that do not match
- L	display a matching filename

2. SED command

(1), the introduction of the order

Sed is a good file processing tool , itself is a pipe command, mainly in the behavior of the unit to deal with, you can replace, delete, add, select

For specific tasks, let's take a look at the use of SED

The SED command line format is:
sed [-nefri] ' command ' Enter text

(2), parameter

Common options:
-N: Use Quiet (silent) mode. In general sed usage, all data from stdin is generally listed on the screen.

However, if you add the- n parameter, only the line (or action) that is specifically handled by SED will be listed .

-E: SED action edit directly on instruction column mode;

-F: Directly write the action of SED in a file, the-f filename can perform the SED action in filename;

-r:sed's actions support the syntax of extended formal notation. (Presupposition is the basic formal representation of French law)

-I: Directly modify the contents of the file read, not by the screen output.

Common commands:
A: New, a can be followed by a string, and these strings will appear on the new line (the current line) ~

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 of the drums;

I: Insert, I can be followed by strings, and these strings will appear on a new line (the current line);

p: Print, that is, to print out a selection of data. Normally p will work with the parameter Sed-n ~

S: Content replacement.

(3), instance (file name is test)

(1) Delete a row

Sed ' 1d ' test   #删除第一行
sed ' $d ' test   #删除最后一行
sed ' 1,2d ' test #删除第一行到第二行
sed ' 2, $d ' Test #删除第二行到最后一行 <span style= "Font-family:simsun; Background-color:rgb (255, 255, 255); > </span>

Delete a matching row

Sed-i '/Match string/d '  filename  (Note: If the matching string is a variable, you need "" instead of "")

(2) Display a row

Sed-n ' 1p ' test    #显示第一行
sed-n ' $p ' test    #显示最后一行
sed-n ' 1,2p ' test  #显示第一行到第二行
sed-n ' 2, $p ' test< c8/> #显示第二行到最后一行

(3) Use mode to query

Sed-n '/ruby/p ' test    #查询包括关键字ruby所在所有行
sed-n '/\$/p ' Test   #查询包括关键字 $ all rows, using backslashes \ Masking special meaning

(4) Adding one or more lines of string

Sed ' 1a drink tea ' test   #第一行后增加字符串 "Drink tea"
sed ' 1,3a drink tea ' test #第一行到第三行后增加字符串 "drink tea"
sed ' 1a D Rink Tea\nor Coffee ' test   #第一行后增加多行, using line breaks \ n

(5) Instead of one or more lines

SED ' 1c hi ' test                #第一行代替为Hi
sed ' 1,2c hi ' Test             #第一行到第二行代替为Hi

(6) Replacing a part of a row

Format: sed ' s/the string to be replaced/the new string/g '   (the string to be replaced can be in regular expression)
sed-n '/ruby/p ' test | sed ' s/ruby/bird/g '    #替换ruby为bird
sed-n '/ruby/p ' test | sed ' s/ruby//g '        #删除ruby

(7) Replace a string in a matching row

Sed-i '/matching string/s/replacement source string/replacement destination string/g ' filename

(8) inserting

Sed-i ' $a bye ' ab         #在文件ab中最后一行直接输入 "Bye"

That's about it, so use it to find something else.