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193 lines
7.0 KiB
Markdown
193 lines
7.0 KiB
Markdown
[#]: collector: (lujun9972)
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[#]: translator: ( pityonline )
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[#]: reviewer: ( )
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[#]: publisher: ( )
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[#]: url: ( )
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[#]: subject: (How To Remove/Delete The Empty Lines In A File In Linux)
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[#]: via: (https://www.2daygeek.com/remove-delete-empty-lines-in-a-file-in-linux/)
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[#]: author: (Magesh Maruthamuthu https://www.2daygeek.com/author/magesh/)
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How To Remove/Delete The Empty Lines In A File In Linux
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======
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Some times you may wants to remove or delete the empty lines in a file in Linux.
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If so, you can use the one of the below method to achieve it.
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It can be done in many ways but i have listed simple methods in the article.
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You may aware of that grep, awk and sed commands are specialized for textual data manipulation.
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Navigate to the following URL, if you would like to read more about these kind of topics. For **[creating a file in specific size in Linux][1]** multiple ways, for **[creating a file in Linux][2]** multiple ways and for **[removing a matching string from a file in Linux][3]**.
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These are fall in advanced commands category because these are used in most of the shell script to do required things.
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It can be done using the following 5 methods.
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* **`sed Command:`** Stream editor for filtering and transforming text.
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* **`grep Command:`** Print lines that match patterns.
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* **`cat Command:`** It concatenate files and print on the standard output.
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* **`tr Command:`** Translate or delete characters.
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* **`awk Command:`** The awk utility shall execute programs written in the awk programming language, which is specialized for textual data manipulation.
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* **`perl Command:`** Perl is a programming language specially designed for text editing.
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To test this, i had already created the file called `2daygeek.txt` with some texts and empty lines. The details are below.
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```
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$ cat 2daygeek.txt
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2daygeek.com is a best Linux blog to learn Linux.
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It's FIVE years old blog.
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This website is maintained by Magesh M, it's licensed under CC BY-NC 4.0.
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He got two GIRL babys.
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Her names are Tanisha & Renusha.
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```
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Now everything is ready and i’m going to test this in multiple ways.
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### How To Remove/Delete The Empty Lines In A File In Linux Using sed Command?
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Sed is a stream editor. A stream editor is used to perform basic text transformations on an input stream (a file or input from a pipeline).
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```
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$ sed '/^$/d' 2daygeek.txt
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2daygeek.com is a best Linux blog to learn Linux.
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It's FIVE years old blog.
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This website is maintained by Magesh M, it's licensed under CC BY-NC 4.0.
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He got two GIRL babes.
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Her names are Tanisha & Renusha.
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```
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Details are follow:
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* **`sed:`** It’s a command
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* **`//:`** It holds the searching string.
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* **`^:`** Matches start of string.
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* **`$:`** Matches end of string.
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* **`d:`** Delete the matched string.
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* **`2daygeek.txt:`** Source file name.
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### How To Remove/Delete The Empty Lines In A File In Linux Using grep Command?
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grep searches for PATTERNS in each FILE. PATTERNS is one or patterns separated by newline characters, and grep prints each line that matches a pattern.
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```
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$ grep . 2daygeek.txt
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or
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$ grep -Ev "^$" 2daygeek.txt
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or
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$ grep -v -e '^$' 2daygeek.txt
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2daygeek.com is a best Linux blog to learn Linux.
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It's FIVE years old blog.
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This website is maintained by Magesh M, it's licensed under CC BY-NC 4.0.
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He got two GIRL babes.
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Her names are Tanisha & Renusha.
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```
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Details are follow:
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* **`grep:`** It’s a command
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* **`.:`** Replaces any character.
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* **`^:`** matches start of string.
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* **`$:`** matches end of string.
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* **`E:`** For extended regular expressions pattern matching.
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* **`e:`** For regular expressions pattern matching.
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* **`v:`** To select non-matching lines from the file.
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* **`2daygeek.txt:`** Source file name.
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### How To Remove/Delete The Empty Lines In A File In Linux Using awk Command?
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The awk utility shall execute programs written in the awk programming language, which is specialized for textual data manipulation. An awk program is a sequence of patterns and corresponding actions.
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```
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$ awk NF 2daygeek.txt
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or
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$ awk '!/^$/' 2daygeek.txt
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or
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$ awk '/./' 2daygeek.txt
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2daygeek.com is a best Linux blog to learn Linux.
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It's FIVE years old blog.
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This website is maintained by Magesh M, it's licensed under CC BY-NC 4.0.
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He got two GIRL babes.
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Her names are Tanisha & Renusha.
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```
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Details are follow:
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* **`awk:`** It’s a command
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* **`//:`** It holds the searching string.
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* **`^:`** matches start of string.
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* **`$:`** matches end of string.
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* **`.:`** Replaces any character.
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* **`!:`** Delete the matched string.
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* **`2daygeek.txt:`** Source file name.
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### How To Delete The Empty Lines In A File In Linux using Combination of cat And tr Command?
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cat stands for concatenate. It is very frequently used in Linux to reads data from a file.
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cat is one of the most frequently used commands on Unix-like operating systems. It’s offer three functions which is related to text file such as display content of a file, combine multiple files into the single output and create a new file.
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Translate, squeeze, and/or delete characters from standard input, writing to standard output.
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```
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$ cat 2daygeek.txt | tr -s '\n'
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2daygeek.com is a best Linux blog to learn Linux.
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It's FIVE years old blog.
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This website is maintained by Magesh M, it's licensed under CC BY-NC 4.0.
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He got two GIRL babes.
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Her names are Tanisha & Renusha.
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```
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Details are follow:
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* **`cat:`** It’s a command
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* **`tr:`** It’s a command
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* **`|:`** Pipe symbol. It pass first command output as a input to another command.
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* **`s:`** Replace each sequence of a repeated character that is listed in the last specified SET.
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* **`\n:`** To add a new line.
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* **`2daygeek.txt:`** Source file name.
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### How To Remove/Delete The Empty Lines In A File In Linux Using perl Command?
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Perl stands in for “Practical Extraction and Reporting Language”. Perl is a programming language specially designed for text editing. It is now widely used for a variety of purposes including Linux system administration, network programming, web development, etc.
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```
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$ perl -ne 'print if /\S/' 2daygeek.txt
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2daygeek.com is a best Linux blog to learn Linux.
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It's FIVE years old blog.
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This website is maintained by Magesh M, it's licensed under CC BY-NC 4.0.
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He got two GIRL babes.
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Her names are Tanisha & Renusha.
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```
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--------------------------------------------------------------------------------
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via: https://www.2daygeek.com/remove-delete-empty-lines-in-a-file-in-linux/
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作者：[Magesh Maruthamuthu][a]
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选题：[lujun9972][b]
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译者：[pityonline](https://github.com/pityonline)
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校对：[校对者ID](https://github.com/校对者ID)
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本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
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[a]: https://www.2daygeek.com/author/magesh/
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[b]: https://github.com/lujun9972
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[1]: https://www.2daygeek.com/create-a-file-in-specific-certain-size-linux/
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[2]: https://www.2daygeek.com/linux-command-to-create-a-file/
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[3]: https://www.2daygeek.com/empty-a-file-delete-contents-lines-from-a-file-remove-matching-string-from-a-file-remove-empty-blank-lines-from-a-file/
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