How to Use Exit Codes in Shell Scripts
Every command returns an exit status, also commonly referred to as return status or exit code. A successful command exits with an exit status of 0.
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How to Use Positional Parameters in Bash Scripts
While user-defined variables provide a means for script authors to create containers to store values used by a script, …
Ultimate Guide to DNS Troubleshooting in Linux
In this troubleshooting post, we will exaplin: Usage of dig command to troubleshoot common DNS problems. Identify …
What Are the Configuration Files for Postfix
Postfix is a powerful but easy-to-configure mail server. It is the default mail server in CentOS/RHEL 7. Postfix is …
Beginners Guide to Writing Bash Shell Scripts in Linux
Many simple day-to-day system administration tasks can be accomplished by the numerous Linux command-line tools …
How to Debug the Shell Scripts in Linux
Inevitably, administrators who write, use, or maintain shell scripts will encounter bugs with a script. Bugs are …
How to Iterate With Bash "For" Loop
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How to Use Variable in Bash Scripts
As the complexity of a shell script increases, it is often helpful to make use of variables. A variable serves as a …
Understanding Bash Shell Expansion - Command Substitution and Arithmetic Expansion
Aside from variable expansion, the Bash shell offers several other types of shell expansion features. Of these, command …
Beginners Guide to DNS
This post touch bases upon: Explain the hierarchical structure of the Domain Name System (DNS). Differentiate between …
Beginners Guide to Firewalld's "Rich Language Rules"
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