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This article introduces the knowledge of "how to delete the blank lines in the file in the Linux system". In the operation of actual cases, many people will encounter such a dilemma, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

The following five ways can be done.

Sed: a stream editor that filters and replaces text.

Grep: outputs the line to which it matches.

Cat: merge the files and print the contents to standard output.

Tr: replace or delete characters.

The awk:awk tool is used to execute programs written in the awk language, specifically for text processing.

Perl:Perl is a programming language for processing text.

I created a 2daygeek.txt file to test these commands. Here are the contents of the file.

$cat 2daygeek.txt2daygeek.com is a best Linux blog to learn Linux. It's FIVE years old blog. This website is maintained by Magesh M, it's licensed under CC BY-NC 4.0. He got two GIRL babys. Her names are Tanisha & Renusha.

Now that everything is in place, we are ready to start verifying it in a variety of ways.

Use the sed command

Sed is a stream editor stream editor. The stream editor is used to edit the text in the input stream (file or pipe).

$sed'/ ^ $/ d' 2daygeek.txt2daygeek.com is a best Linux blog to learn Linux.It's FIVE years old blog.This website is maintained by Magesh M, it's licensed under CC BY-NC 4.0.He got two GIRL babes.Her names are Tanisha & Renusha.

The following are the details of the command deployment:

Sed: the command itself.

/ /: tag matching range.

^: matches the beginning of the string.

$: matches the end of the string.

D: delete the matching string.

2daygeek.txt: source file name.

Use the grep command

Grep can search through files through regular expressions. The expression can be a character separated by one or more lines of blank lines, and grep prints all matches.

$grep. 2daygeek.txtor$ grep-Ev "^ $" 2daygeek.txtor$ grep-v-e'^ $'2daygeek.txt2daygeek.com is a best Linux blog to learn Linux.It's FIVE years old blog.This website is maintained by Magesh M, it's licensed under CC BY-NC 4.0.He got two GIRL babes.Her names are Tanisha & Renusha.

The following are the details of the command deployment:

Grep: the command itself.

Replace any character.

^: matches the beginning of the string.

$: matches the end of the string.

E: use extended regular matching patterns.

E: use regular regular matching patterns.

V: reverse matching.

2daygeek.txt: source file name.

Use the awk command

Awk can execute scripts written in the awk language, mostly dedicated to processing text. An awk script is a combination of a series of awk commands and rules.

$awk NF 2daygeek.txtor$ awk'! / ^ $/ '2daygeek.txtor$ awk' /. / '2daygeek.txt2daygeek.com is a best Linux blog to learn Linux.It's FIVE years old blog.This website is maintained by Magesh M, it's licensed under CC BY-NC 4.0.He got two GIRL babes.Her names are Tanisha & Renusha.

The following are the details of the command deployment:

Awk: the command itself.

/ /: tag matching range.

^: matches the beginning of the string.

$: matches the end of the string.

.: matches any character

!: delete the matching string.

2daygeek.txt: source file name.

Use a combination of cat and tr commands

Cat is the abbreviation for concatenated (spliced) concatenate. It is often used to read the contents of a file in Linux.

Cat is one of the most frequently used commands in Unix-like systems. It provides three common functions for dealing with text files: displaying the contents of the file, splicing multiple files into one, and creating a new file.

Tr can convert, compress, or delete characters from standard input, and then redirect them to standard output.

$cat 2daygeek.txt | tr-s'\ n'2daygeek.com is a best Linux blog to learn Linux.It's FIVE years old blog.This website is maintained by Magesh M, it's licensed under CC BY-NC 4.0.He got two GIRL babes.Her names are Tanisha & Renusha.

The following are the details of the command deployment:

Cat: the cat command itself.

Tr: the tr command itself.

|: pipe symbol. It can use the standard output of the previous command as the standard input of the next command.

S: replace any number of repeating characters in the dataset into one.

\ n: add a new line feed.

2daygeek.txt: source file name.

Use the perl command

Perl represents a useful extraction and reporting language, Practical Extraction and Reporting Language. At the beginning, Perl was designed as a programming language dedicated to text processing, and now it has been extended to many fields such as Linux system management, network programming and website development.

$perl-ne 'print if /\ Splink' 2daygeek.txt2daygeek.com is a best Linux blog to learn Linux.It's FIVE years old blog.This website is maintained by Magesh M, it's licensed under CC BY-NC 4.0.He got two GIRL babes.Her names are Tanisha & Renusha.

The following are the details of the command deployment:

Perl: perl command.

N: read the data line by line.

E: execute a command.

Print: print information.

If: if conditional branch.

/ /: tag matching range.

\ s: matches any non-white space character.

2daygeek.txt: source file name.

This is the end of the introduction of "how to delete blank lines in a file in the Linux system". Thank you for your reading. If you want to know more about the industry, you can follow the website, the editor will output more high-quality practical articles for you!

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