# Linux Fundamentals (DevOps)

> File system, permissions, users & groups, package managers, systemd, logs, processes

- 22 interview questions
- Junior
- [Interview Questions: DevOps](https://sharpskill.dev/en/technologies/devops/interview-questions.md)

## 1. What is the /etc directory in Linux?

**Answer**

The /etc directory contains system and application configuration files installed on the system. It is a standard location where administrators find configuration files to modify to customize system behavior. Common files include /etc/passwd for users, /etc/hosts for local DNS resolution, and /etc/fstab for file system mounting.

## 2. What is the role of the /var directory in Linux?

**Answer**

The /var directory stores variable data that changes frequently during system operation. This includes logs in /var/log, caches in /var/cache, print spools in /var/spool, and local databases. The name var comes from variable because its content varies constantly unlike static files in /usr or /etc.

## 3. Which command lists files and directories in the current directory?

**Answer**

The ls command lists files and directories in the current directory. It can be used with various options like -l for detailed display showing permissions, -a to show hidden files starting with a dot, and -h to display sizes in human-readable format. It is one of the most commonly used Linux commands in daily work.

## 19 more questions available

- What does the first character represent in file permissions displayed by ls -l?
- Which command changes the current working directory?

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## Other DevOps interview topics

- [Version Control & Git](https://sharpskill.dev/en/technologies/devops/interview-questions/version-control-git.md): 20 questions, Junior
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- [GitHub Actions](https://sharpskill.dev/en/technologies/devops/interview-questions/github-actions.md): 22 questions, Mid-Level
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- [Terraform Advanced](https://sharpskill.dev/en/technologies/devops/interview-questions/terraform-advanced.md): 22 questions, Mid-Level
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