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LaTerral Williams
LaTerral Williams

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🐧Real-World Linux: A Beginner's Journey Through the Command Line

#cloudwhistler #cloud #linux #opensource

Scenario: You’ve just been onboarded as a junior system administrator at a small tech company. Your task? Set up a shared project workspace for a new development team, manage users and permissions, prepare logs, and automate a few maintenance tasks. You’ll walk through everything using essential Linux commands.

Let’s get into it. One task, many tools. 💪

📑 Table of Contents

🗂 Step 1: Organizing the Workspace

First, let's create the folder structure for the project.

mkdir -p /projects/devteam/logs
cd /projects/devteam
pwd
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✅ mkdir creates the project directories.

✅ cd moves into the workspace.

✅ pwd confirms your current path.

You’ll list your files often, so:

ls -l
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✅ ls -l shows detailed contents (permissions, ownership, size, etc).

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📝 Step 2: Creating and Managing Files

Let’s make some placeholder files.

touch README.md notes.txt dev.log
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✅ touch creates empty files. Now let’s write a quick note.

echo "Welcome to the DevTeam workspace!" > README.md
cat README.md
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✅ cat displays file content. Need to view just part of a large log?

head -n 3 dev.log
tail -n 3 dev.log
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✅ head and tail help preview file tops and bottoms.

You can also use wc to count lines, words, and characters:

wc -l notes.txt
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Remember the files we've created are empty. You may try the following cmds to enter mock text for testing.

yes "Dev Log Entry" | head -n 20000000 > dev.log
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This writes Dev Log Entry to dev.log 20 million times. Please do not try to cat this file!

If you want to enter text manually. You may try:

cat > notes.txt << EOF
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This allows more control.

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👥 Step 3: User and Group Setup

Now, let’s add some team members.

sudo groupadd devs
sudo useradd -m -G devs alice
sudo useradd -m -G devs bob
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✅ groupadd creates a group.

✅ useradd creates users and adds them to the devs group.

Set their passwords:

sudo passwd alice
sudo passwd bob
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Need to promote Alice to sudo?

sudo usermod -aG wheel alice
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✅ usermod modifies user groups.

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🔐 Step 4: Managing Permissions

Now that the team exists, let's adjust access to the project folder.

sudo chown -R root:devs /projects/devteam
sudo chmod -R 2775 /projects/devteam
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✅ chown sets group ownership.

✅ chmod 2775 allows group read/write/execute and preserves the group via SGID (2).

Add the sticky bit to logs so only owners can delete their files:

sudo chmod +t /projects/devteam/logs
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🧝 Step 5: Fine-Grained Access with ACLs

Bob needs write access to notes.txt but Alice should only read.

sudo setfacl -m u:bob:rw notes.txt
sudo setfacl -m u:alice:r-- notes.txt
getfacl notes.txt
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✅ setfacl customizes file access.

✅ getfacl reviews who has what permissions.

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🔍 Step 6: Finding and Searching Files

Let’s locate the README.md file and check its contents.

find /projects -name README.md
grep "DevTeam" README.md
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✅ find helps locate files.

✅ grep searches for specific patterns or words.

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📦 Step 7: Archiving and Compression

You want to back up the workspace before launch:

sudo tar -cvf devteam_backup.tar /projects/devteam
sudo gzip devteam_backup.tar
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✅ tar archives files.

✅ gzip compresses them.

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You could also try other formats:

sudo bzip2 notes.txt
sudo xz README.md
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I had to do a bit of research on why I received this message. If you receive this please do additional research to resolve because I am explaining this through my own interpretation of what I read.

My understanding is xz zip flags executable files with setuid or setgid because as you know these files may be run with elevated privileges based on the uid or gid and this presents a security risk. So let's remove the x permissions from README.md and see if we are able to zip it.


sudo chmod ugo-x README.md
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I received the same message. So, let's try removing the sgid bit. I noticed that S in the group permissions and the error tells me the issue, [insert uncomfortable laugh], but live, learn, linux...

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sudo chmod g-s README.md
sudo xz README.md
sudo chmod g+s README.md
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I was able to zip the file successfully and reapply the sgid bit. I left it as rw because it is a README.md, there is not a need for it to be executable.

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To decompress:

gunzip devteam_backup.tar.gz
bunzip2 notes.txt.bz2
unxz README.md.xz
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⏱️ Step 8: Scheduling Maintenance Jobs

You want to archive logs every night and delete them at the end of the week.

Schedule a one-time test with at:

echo "tar -czf logs.tar.gz /projects/devteam/logs" | at 22:00
atq  # List jobs
atrm 1  # Remove job #1 if needed
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Set up a recurring cron job:

crontab -e
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Add this line to run a script every day at midnight:

0 0 * * * /usr/local/bin/archive_logs.sh
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✅ at handles one-time jobs.

✅ crontab handles recurring jobs.

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at, cron, crontab are a bit too lengthy to cover in an already lengthy article, but here's another article I wrote covering them if you are curious: Linux Timecop

📘 Step 9: Help Along the Way

Never forget the man command. It’s your best friend:

man chmod
man tar
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You likely don't need a lot of coverage about man, but if you are interested in additional documentation tools, here's another article discussing man, info, tldr and wikit: Linux Documentation Tools

✅ Summary

You’ve just:

  • Created a directory structure
  • Managed users and permissions
  • Applied ACLs and special bits
  • Searched, archived, compressed
  • Scheduled automated tasks

All using beginner-friendly Linux commands in a real-world scenario.

✍️ Final Thought

If you're just starting your Linux journey, this scenario gives you a full-circle experience of what a real-world task may look like, from setup to automation. Try these commands in a VM or test environment, and you’ll quickly build confidence!

💬 Let’s Connect - My LinkedIn

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