To ensure that scripts are not easily derailed by unexpected conditions, it is good practice for script authors to not make assumptions regarding inputs, such as command-line arguments, user inputs, command substitutions, variable expansions, filename expansions, etc.
Every command returns an exit status, also commonly referred to as return status or exit code. A successful command …
While user-defined variables provide a means for script authors to create containers to store values used by a script, …
In this troubleshooting post, we will exaplin: Usage of dig command to troubleshoot common DNS problems. Identify …
Postfix is a powerful but easy-to-configure mail server. It is the default mail server in CentOS/RHEL 7. Postfix is …
Many simple day-to-day system administration tasks can be accomplished by the numerous Linux command-line tools …
Inevitably, administrators who write, use, or maintain shell scripts will encounter bugs with a script. Bugs are …
System administrators often encounter repetitive tasks in their day-to-day activities. Repetitive tasks can take the …
As the complexity of a shell script increases, it is often helpful to make use of variables. A variable serves as a …
Aside from variable expansion, the Bash shell offers several other types of shell expansion features. Of these, command …
This post touch bases upon: Explain the hierarchical structure of the Domain Name System (DNS). Differentiate between …