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Bash Split String (+ Shell Scripts)

Bash Split String

This article will show you how to split a string at a given delimiter in Bash/Shell scripts and show some examples. Splitting strings is a handy function to have available when crafting your scripts. CSV (Comma Separated Values) is a common format in which data is made available online, where data fields in a table are separated by (surprise) commas. You may also simply be looking to split a sentence into words at the spaces, or split paragraphs into sentences at the period, and so … Read more

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Use wc to Count the Characters/Words/Lines [Linux/Bash]

Bash wc command count words

The wc program can be used in Bash scripts and from the Linux command line to count the number of bytes, characters, words, or lines in a file. Here’s how to use it, with examples. wc Program Syntax The syntax for the wc command is as follows: wc OPTIONS FILE Note that: OPTIONS should be provided from the below table of available options FILE is the path to the file which will have the contents counted More than one file can be specified If more than one file is specified, the total … Read more

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How to Use the Bash echo Command, With Examples

How to use the echo command in Bash

The Bash echo command serves a simple purpose – it outputs (echos) text. Here’s how to use it, with examples. echo Command Syntax The echo command is very simple and has the following syntax: echo OPTIONS TEXT Note that: OPTIONS should be one of the following options -n Do not output a trailing newline -e Enable interpretation of backslash escapes This means that escape characters can be used to insert special characters into the output \\ backslash \a alert (BEL) \b backspace \c produce no further output \e escape \f form feed \n new line \r carriage return \t horizontal tab \v vertical … Read more

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How to Use while Loops in Bash/Shell Scripts [Examples]

Bash while Loops

This article will show you how to use while loops in Bash/Shell scripts, and provides some code examples. Bash scripts let you automate tasks in the linux shell. Often, you’ll want to repeat a task for a set of data or repeated user input – that’s what while loops are for – they let you loop or iterate over a sequence of data or input, making it easy to build scripts that repeat a set of actions. The while loop syntax demonstrated below will also work for the Zsh shell and … Read more

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How to Use the Bash case Statement, With Examples

How to Use Bash case Statements

The case statement is used to choose which code to execute based on the value of a variable or expression. Here is how to use it in your Bash scripts. What Does the case Statement Do? The case statement is a convenient alternative to using multiple if/if else statements when you are deciding what action to take based on the value of a variable or expression. For example, if you have a variable called weekday, you can executed different code based on which day of the week is named in the variable, … Read more

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LinuxScrew’s Linux Shell/Bash Scripting Tips

Bash script hot tips

Here are some handy tips to keep in mind when writing your shell scripts in Linux. Shell scripts are a versatile way to automate your workflows in Linux (and MacOS, and now Windows, with the Windows Subsystem for Linux). Shell scripting syntax and behaviour does have its quirks, and there are useful shortcuts you can take as well to simplify your scripts. Bash Scripting Tips These tips are collected from around the internet, with a few of my own thrown in. Bash scripts will keep … Read more

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Linux Tip: Using visudo to Avoid Costly Mistakes

Linux visudo

Linux Tip: Use visudo to Edit the sudoers File to Avoid Costly Mistakes This article will show you how to use visudo to edit the sudoers file to grant root access to users – and protect against making mistakes that could lock you out of your Linux system forever. What is the sudoers File? The sudoers file defines which users have access to the sudo command on Linux systems. The file is located at: /etc/sudoers …and it looks like this: # # This file MUST be edited with the ‘visudo’ command as root. # # … Read more

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How to Unzip Files in Linux with the unzip Command

Linux unzip

We’ve zipped files from the Linux command line; now, let’s unzip them. This short article will show you how. Zipping Files Zipping files is common parlance for compressing one or more files or directories into a .zip file – a compressed file format. We cover how to do that in this article, so there’s no need to repeat too much of it here. The Unzip Command The unzip command may not be installed on your system by default. If it isn’t, it can be installed on Debian/Ubuntu-based OS by running: … Read more

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How to Execute PHP from the Command Line (Bash/Shell)

Execute PHP from the Command Line/Bash

This article will quickly run through the ways PHP can be used from the Bash shell/command line, with examples. PHP is usually used for generating content to be served on the web – but it can also be used from the command line. This is usually done for the purposes of testing or finding out information about the PHP environment – but PHP can also be used for writing command-line scripts (though, again, it’s not really done that frequently – probably because there are better … Read more

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Bash Scripts Set Environmental Variables with EXPORT [HowTo]

Bash Set/Export Environmental Variable

This tutorial will show you how to set environmental variables in Bash/Shell scripts using the export keyword. Generally, variables declared in Bash/Shell scripts exist only within the scope of that running Bash/Shell script. To make them available elsewhere, they can be set as an environmental variable – meaning that the variable will be available when executing commands outside of the script on your system – for example, making the variable available from the command line after the script has completed. The export keyword does this – … Read more