The Linux learning sed grep

1. The most important function of the SED command is to replace it with the following document content as an example

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In Vim's command-line mode, you can use:%s/some/more/to replace some in the document with more

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The SED command is much more convenient: sed ' s/some/more/g ' data.txt--there is no change to the original document, up to a preview

Sed-i ' s/some/more/g ' data.txt-------have the I parameter to save the changes directly in the document

Sed ' s/^/&id/g ' data.txt add id+ spaces in each line of the document

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Cat Data.txt | Grep-v ' ^$ ' | Sed ' s/^/&id/g '---the line of non-whitespace lines in each row of the outfit add id,^ symbol to start with

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You can see the space line is not there, it is grep-v ' ^$ ' cause, grep will be in the following

Sed ' s/$/& id/g ' data.txt adds a space +id,$ at the end of each line of the document to indicate the end

Sed '/some/i ########################## ' data.txt add a row before the row with some #,i parameter

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Sed '/some/a ########################## ' data.txt add a line after the row with some #,a parameter

Sed-n '/some/p ' data.txt print rows containing some,-n is for line operation, p parameter is agreed, SED is responsible for selecting

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You can also select the specified line: sed-n ' 1,5p ' data.txt print 1-5 lines

Here's how to specify the document in conjunction with other commands:

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The above is the original document, the ultimate goal is to select the largest and smallest number in the document

Cat Number.txt | Sed ' s//\n/g ' | Grep-v "^$" | Sort-nr | Sed-n ' 1p; $p '

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Now to dismantle these commands.

Cat Number.txt | Sed ' s//\n/g '--replace the characters in the document with a newline character so that all the numbers become a column

Cat Number.txt | Sed ' s//\n/g ' | Grep-v "^$" will be lined up in a column of blank lines to remove, excluding the first is empty

Cat Number.txt | Sed ' s//\n/g ' | Grep-v "^$" | Sort-nr sort all numbers from big to small

Cat Number.txt | Sed ' s//\n/g ' | Grep-v "^$" | Sort-nr | Sed-n ' 1p; $p ' Print out the first line and the last line;

Where the $ represents the end of the; indicates that the front and back are separate printing is not continuous use, it is continuous printing multi-line sed-n ' 1,5p ' such

The role of the 2.GREP command is primarily to match characters

Cat Number.txt | grep "4" indicates that the line containing 45 is matched

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Cat Number.txt | Grep-v "4" means excluding the line containing the 4 character, and there is no difference between "" and "

grep command to view: RPM-QA When installing software | grep mysql---Check out some of the relevant installation packages for MySQL

Use SED command to modify certain files: Sed-i '/selinux/s/enforcing/disabled/'/etc/selinux/config---permanently off SELINUX

This article is from the "Sed for linux commands" blog, so be sure to keep this source http://beforce.blog.51cto.com/3335637/1912347

The Linux learning sed grep