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翻译完成 How To Remove-Delete The Empty Lines In A File In Linux.md
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[#]: 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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@ -0,0 +1,194 @@
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[#]: 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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在 Linux 中如何删除文件中的空行
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======
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有时你可能需要在 Linux 中删除某个文件中的空行。
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如果是的，你可以使用下面方法中的其中一个。
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有很多方法可以做到，但我在这里只是列举一些简单的方法。
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你可能已经知道 `grep`，`awk` 和 `sed` 命令是专门用来处理文本数据的工具。
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如果你想了解更多关于这些命令的文章，请访问这几个 URL。**[在 Linux 中创建指定大小的文件的几种方法][1]**，**[在 Linux 中创建一个文件的几种方法][2]** 以及 **[在 Linux 中删除一个文件中的匹配的字符串][3]**。
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这些属于高级命令，它们可用在大多数 shell 脚本中执行所需的操作。
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下列 5 种方法可以做到。
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* **`sed:`** 过滤和替换文本的流编辑器。
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* **`grep:`** 输出匹配到的行。
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* **`cat:`** 合并文件并打印内容到标准输出。
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* **`tr:`** 替换或删除字符。
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* **`awk:`** awk 工具用于执行 awk 语言编写的程序，专门用于文本处理。
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* **`perl:`** Perl 是一种用于处理文本的编程语言。
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我创建了一个 `2daygeek.txt` 文件来测试这些命令。下面是文件的内容。
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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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现在一切就绪，我们准备开始用多种方法来验证。
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### 使用 sed 命令
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sed 是一个<ruby>流编辑器<rt>stream editor</rt></ruby>。流编辑器是用来编辑输入流（文件或管道）中的文本的。
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```
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$ sed '/^$/d' 2daygeek.txt
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2daygeek.com is a best Linux blog to learn Linux.
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It's FIVE years old blog.
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This website is maintained by Magesh M, it's licensed under CC BY-NC 4.0.
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He got two GIRL babes.
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Her names are Tanisha & Renusha.
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```
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以下是命令展开的细节：
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* **`sed:`** 该命令本身。
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* **`//:`** 标记匹配范围。
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* **`^:`** 匹配字符串开头。
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* **`$:`** 匹配字符串结尾。
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* **`d:`** 删除匹配的字符串。
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* **`2daygeek.txt:`** 源文件名。
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### 使用 grep 命令
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`grep` 可以通过正则表达式在文件中搜索。该表达式可以是一行或多行空行分割的字符，`grep` 会打印所有匹配的内容。
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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 '^$' 2daygeek.txt
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2daygeek.com is a best Linux blog to learn Linux.
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It's FIVE years old blog.
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This website is maintained by Magesh M, it's licensed under CC BY-NC 4.0.
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He got two GIRL babes.
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Her names are Tanisha & Renusha.
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```
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Details are follow:
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以下是命令展开的细节：
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* **`grep:`** 该命令本身。
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* **`.:`** 替换任意字符。
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* **`^:`** 匹配字符串开头。
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* **`$:`** 匹配字符串结尾。
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* **`E:`** 使用扩展正则匹配模式。
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* **`e:`** 使用常规正则匹配模式。
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* **`v:`** 反向匹配。
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* **`2daygeek.txt:`** 源文件名。
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### 使用 awk 命令
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`awk` 可以执行使用 awk 语言写的脚本，大多是专用于处理文本的。awk 脚本是一系列 awk 命令和正则的组合。
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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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以下是命令展开的细节：
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* **`awk:`** 该命令本身。
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* **`//:`** 标记匹配范围。
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* **`^:`** 匹配字符串开头。
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* **`$:`** 匹配字符串结尾。
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* **`.:`** 匹配任意字符。
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* **`!:`** 删除匹配的字符串。
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* **`2daygeek.txt:`** 源文件名。
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### 使用 cat 和 tr 命令 组合
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`cat` 是<ruby>串联（拼接）<rt>concatenate</rt></ruby>的简写。经常用于在 Linux 中读取一个文件的内容。
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cat 是在类 Unix 系统中使用频率最高的命令之一。它提供了常用的三个处理文本文件的功能：显示文件内容，将多个文件拼接成一个，以及创建一个新文件。
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tr 可以将标准输入中的字符转换，压缩或删除，然后重定向到标准输出。
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```
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$ 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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以下是命令展开的细节：
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* **`cat:`** cat 命令本身。
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* **`tr:`** tr 命令本身。
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* **`|:`** 管道符号。它可以将前面的命令的标准输出作为下一个命令的标准输入。
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* **`s:`** 替换标数据集中任意多个重复字符为一个。
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* **`\n:`** 添加一个新的换行。
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* **`2daygeek.txt:`** 源文件名。
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### 使用 perl 命令
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Perl 表示<ruby>实用的提取和报告语言<rt>Practical Extraction and Reporting Language</rt></ruby>。Perl 在初期被设计为一个专用于文本处理的编程语言，现在已扩展应用到 Linux 系统管理，网络编程和网站开发等多个领域。
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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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以下是命令展开的细节：
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* **`perl:`** perl 命令。
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* **`n:`** 逐行读入数据。
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* **`e:`** 执行某个命令。
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* **`print:`** 打印信息。
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* **`if:`** if 条件分支。
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* **`//:`** 标记匹配范围。
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* **`\S:`** 匹配任意非空白字符。
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* **`2daygeek.txt:`** 源文件名。
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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)
|
||||
|
||||
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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|
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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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Reference in New Issue
Block a user