Linux Commands for Beginners: touch cat head tail echo tee

👉 Day 5: revisit to Linux File & Directory Commands As part of my #100DaysOfDevOps journey, today I focused on one of the most important foundations in Linux — managing files and directories efficiently. These commands might look simple, but they are used every single day in real DevOps work. 💻 📁 File Management Commands 🔹 touch – Created files (single, multiple, and even bulk using patterns like linux{1..5}); touch file1 file2 file3 ; touch file{1..8} ; touch file.html file.css 🔹 rm – Learned how to delete files with and without confirmation rm filename; rm file1 file2 (multiple files); rm -f filename (force delete); rm -f file1 file2; rm -f * (all files); 🔹 rm -f – Force delete (no prompts) 🔹 Used patterns like: 🔹 *.txt → delete all text files 🔹a* → delete files starting with “a” 🔹* → delete everything in a directory ⚙️ 📂 Directory (Folder) Management 🔹 mkdir – Created single and multiple folders 🔹 Used {1..5} pattern for bulk folder creation 🔹 rmdir – Removed empty directories 🔹 rm -rf – Removed non-empty directories (powerful command ⚠️) 📋 📄 Listing Files & Understanding Output 🔹 ls – Basic listing of files/folders 🔹 ll – Detailed view with permissions, size, and ownership Learned the difference: ls = simple view ll = detailed view (very useful in troubleshooting) 💡 Key Takeaway: Mastering these basic commands is crucial because file and directory management is at the core of server handling, automation, and deployments in DevOps. Every small command is building my confidence step by step 🔥 #100DaysOfDevOps #DevOpsJourney #Linux #LinuxCommands #CloudLearning #LearningInPublic #TechSkills #DevOps

🚀 Day 10 of My DevOps Journey — Linux Revision Today was dedicated to revising all the Linux concepts I’ve learned so far and strengthening my fundamentals. 🐧 Topics Revised ✔ Linux history & popular distros ✔ Filesystem hierarchy (/etc, /var, /home, /boot, /tmp) ✔ Navigation commands: ls cd pwd ✔ User & group management: useradd userdel usermod groupadd ✔ Permissions: chmod chown chgrp ✔ File operations: touch cp mv rm mkdir ✔ Search tools: grep awk find ✔ Networking tools: ping nslookup dig curl wget ✔ Process monitoring: ps top htop ✔ Disk & volume management: df -h mount 💻 Hands-On Practice Repeated commands on a Linux server to improve speed, confidence, and command-line understanding. 📌 Key Insight: Revision is where learning becomes mastery. Repeating basics builds a strong foundation for advanced DevOps tools. — Day 10 complete 🔥 #DevOpsJourney #Linux #Revision #DevOps #LearningInPublic #FutureEngineer

Day 11 of #90DaysOfDevOps 🚀 Linux File Ownership: The Other Half of Access Control Permissions tell Linux what can be done to a file. Ownership tells Linux who those permissions apply to. Both must be correct. One wrong ownership in prod can break an entire deployment. What I practiced today: → Identified owner and group columns using `ls -l` → Changed file owner with `chown` → Changed file group with `chgrp` → Changed both owner and group in one command → Applied ownership recursively to an entire directory tree → Set different ownership per file across a multi-team project Commands That Matter: ✅ `chown user file` — change user owner only ✅ `chgrp group file` — change group only ✅ `chown user:group file` — change both in one command ✅ `chown -R user:group dir/` — recursive, applies to all files inside ✅ `ls -lR` — verify ownership across entire directory tree 💡 Key Insight: `chown -R` without the `-R` flag only changes the directory itself — not the files inside. Everything looks fine until your app tries to access a file and gets `Permission denied`. Always use `-R` for directories. 🔑 Mindset Shift: Don’t chown files to individual users in shared environments. Assign to a group. Manage membership. That scales. That’s how production teams operate. #90DaysOfDevOps #DevOpsKaJosh #TrainWithShubham #Linux #DevOps #LearningInPublic

Most beginners think Linux is just an operating system. I thought the same… until today. Day 1 of learning DevOps — and I realized Linux is actually a whole ecosystem. Here’s what I understood 👇 There isn’t just “one Linux”. There are different families, each built for different purposes: 🔴 Red Hat Family - Used mostly in enterprises - Fedora → testing ground - CentOS → close to RHEL - Uses "yum" package manager 🟢 SUSE Family - Popular in retail environments - Uses "zypper" (RPM-based) - YaST helps in system administration 🔵 Debian Family - Base for Ubuntu - Uses "APT" package manager - Widely used in cloud environments --- Then I learned some core concepts: • Kernel → the bridge between hardware and software • Distribution → complete OS (like Ubuntu, Fedora) • Bootloader → starts the system (GRUB) • Services → background processes (like httpd) • Filesystem → how data is stored (ext3, ext4) --- 💡 The way I see it now: Linux is like a restaurant kitchen 🍽️ - Kernel = Head chef - Distribution = Full menu - Services = Staff working in background - Filesystem = Storage room Everything works together to serve one goal. --- Still learning, but this changed how I see Linux completely. Anyone else starting their DevOps journey? Let’s connect 🤝 #DevOps #Linux #LearningInPublic #BeginnersJourney

🔐 Still confused about Linux file permissions? This simple trick will make it click instantly. If you've ever seen something like chmod 755 or rwxr-xr-x and wondered what it really means - you're not alone. I used to memorize it… until I actually understood it. Here’s the simplest way to break it down: 👉 Linux permissions are split into 3 groups User (owner) Group Others 👉 Each group has 3 permissions: Read (r = 4) Write (w = 2) Execute (x = 1) 👉 Add them up to get numbers: rwx = 4+2+1 = 7 rw- = 4+2 = 6 r-x = 4+1 = 5 So when you see: chmod 765 file It means: User → 7 → rwx Group → 6 → rw- Others → 5 → r-x 💡 Pro tip: Think of it as binary → octal → symbolic 111 → 7 → rwx Once you see it this way, permissions stop being confusing and start feeling logical. This is one of those small DevOps/Linux fundamentals that saves you hours of debugging later. If you're learning Linux, don’t skip this - master it early. #Linux #DevOps #CloudComputing #AWS #Kubernetes #SystemAdministration #TechLearning #Programming #DeveloperJourney #OpenSource

🚀 Progress Update on My Linux / DevOps Journey Lately, I’ve been focusing on strengthening my Linux command-line fundamentals — and it’s been a game changer. Instead of rushing into scripting, I decided to build a solid foundation first. Here’s what I’ve been working on: 🔹 File & Directory Management Creating, moving, copying, and organizing files Understanding the difference between files and directories 🔹 Log Analysis (Real-World Practice) Searching logs using grep Counting errors using wc -l Sorting and analyzing logs with sort and uniq 🔹 Key Concepts I’m Learning How pipes (|) pass output between commands Why sort is needed before uniq Extracting specific parts of text using cut Identifying the most frequent errors in logs 🔹 Biggest Realization Building strong command-line skills makes everything easier later — especially scripting and automation. Still exploring concepts like: grep -E cut with delimiters and fields sort -nr uniq -c Taking it step by step and focusing on consistency. #Linux #DevOps #LearningInPublic #SysAdmin #TechJourney

Project 1 of my DevOps portfolio is live on GitHub. Linux Sysadmin Toolkit: four production-grade Bash scripts: disk-monitor.sh: monitors all partitions, logs warnings above 80% threshold, rotates its own log file user-manager.sh: creates, deletes, and lists users with full audit logging backup.sh: timestamped compressed backups with automatic 5-backup retention harden.sh: security audit with pass/fail report and fix hints for every failure Every script: dependency checks, consistent logging format, correct exit codes, no hardcoded values. Built from scratch. Reviewed like production code. Iterated until it passed.

🚀Next step towards devops journey🚀 💻Used to type the same Linux commands again and again… until I learned Shell Scripting 💻 🌠At the beginning, Linux felt a bit confusing with so many commands to remember. But once I understood how shell scripts work, things became much simpler. Now I can: ♣Automate repetitive tasks ♣Write basic scripts ♣Use shebang (#!/bin/bash) properly ♣Display output with echo ♣Work with loops, conditions, and variables 🌠It’s a small step, but it really changed how I use Linux. 🌠I’ve created a simple PPT to explain these concepts in an easy way. 💻You can also check my scripts and resources here: 🔗 GitHub Repository: https://lnkd.in/dxzCa8uB If you're just starting with Linux or DevOps, this might help you 👍 #Linux #ShellScripting #DevOps #Learning #Automation #Beginner #GitHub

📝 Linux for DevOps – Day 01 (Part 1) 🚀 Starting my DevOps journey with Linux basics. Sharing simple notes for beginners 👇 📂 Directory Navigation pwd → Show current directory cd folder → Enter folder cd .. → Go back cd ~ → Home directory cd - → Previous location 📁 List Files & Folders ls → Show files ls -l → Detailed view ls -a → Hidden files ls -d */ → Only folders 📦 Create Files & Folders mkdir DevOps_Lab touch app.log Example: mkdir DevOps_Lab cd DevOps_Lab mkdir logs configs backup touch logs/app.log 🔁 Copy & Move Files cp file backup/ mv file configs/ Small steps every day 💡 Part 2 coming next 👉 (logs, grep, real practice) #Linux #DevOps #BeginnerFriendly #LearningJourney

🔹 Day 04 – Linux Practice: Processes & Services 🔹 Today’s practice was all about strengthening Linux fundamentals with a focus on Docker. I worked through process checks, service inspection, and log troubleshooting — the kind of basics that make a DevOps engineer faster and more confident when things go wrong. ✅ Ran process commands like ps aux | grep docker and pgrep -a dockerd to confirm Docker processes ✅ Inspected the Docker service with systemctl status docker and systemctl list-units --type=service | grep docker ✅ Checked logs using journalctl -u docker and tail -n 50 /var/log/syslog ✅ Captured a mini troubleshooting flow to verify Docker was active and responding The service I inspected today was Docker. I learned how quickly you can verify if the daemon is running, check its logs, and spot issues — all with a few simple commands. 💡 Why this matters: In DevOps, confidence with fundamentals like processes, services, and logs is critical. When production issues arise, you don’t want to waste time searching for basic commands. #90DaysOfDevOps #DevOpsKaJosh #TrainWithShubham #Linux #Docker #DevOps