The SED command for Linux learning notes

To speak and be sensitive to the line--"The Analects of Confucius and Leezen"

The SED command is a text-processing tool that is used to process an input stream. Mastering it can better help manage Linux and process log files.

Usage:

sed [option] ' command ' input stream

Common option:

-N: Quiet mode, generally if you do not have the-n option, all rows in the input stream will be listed, and adding-N will only list the rows processed by ' command '. Normally with command P commands.

-r: The default SED only supports generic regular expressions, and if the-r parameter indicates that the SED supports extended regular expressions.

-I: INSERT, if the input stream is a file stream, modify the content directly in the file instead of outputting it to the screen. (use with caution)

Common ' command ':

A (i): Add (insert) to insert a string after the number of target rows (the previous line).

D:delete, delete the destination row.

P:print, print the target line.

S:substitute, replacing the target string with a new string. Usually this s action can be paired with a regular expression and is similar to a replacement in vim. 1,20s/old/new/g

C: Replace the target line

Example:

Delete:

# sed ' 1d ' #删除第一行
# sed ' $d ' #删除最后一行
# sed ' 1,10d ' #删除第一行到第十行
# sed ' 2, $d ' #删除第二行到最后一行

Show:

. # sed-n ' 1p ' #显示第一行
# sed-n ' $p ' #显示最后一行
# sed-n ' 1,2p ' #显示第一行到第二行
# sed-n ' 2, $p ' #显示第二行到最后一行

# sed–n '/dbird/p ' #打印所有包含dbird line

# sed–n '/\$/p ' #打印所有包含 $ sign Line

Insert:

#sed ' 1,3a drink tea #在1到3行后面插入drink tea, the drink tea is in the first 2,4,6.

#sed 1,3i Drink Tea #在1到3行之前插入drink tea, the drink tea was in the first 1,3,5.

Line substitution:

#sed ' 1,2c Hi ' #将第一到二行替换为Hi

String substitution:

Format: sed ' s/string to replace/new string/g ' (the string to replace can be used with regular expressions)
#sed ' s/dbird/vbird/g ' #替换dbird为vbird
#sed ' s/dbird//g ' #删除dbird

#sed-i '/Match string/d ' filename #直接删除文件filename中的匹配的字符串

The SED command for Linux learning notes