Bashcrawl Armoury: File Permissions and Script Execution

By IT-Journey Team

Learn chmod, file permissions, and script execution in Bashcrawl's Armoury. Brew a health potion and wield a sword for your first combat encounter.

Estimated reading time: 4 minutes

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Table of Contents

Racks of weapons line the walls. Suits of armour stand at attention. But every sword and potion is locked behind a permission barrier — you must learn chmod before you can equip a single item.

🎯 Quest Objectives

• Read ls -l output and interpret permission bits
• Use chmod to make scripts executable
• Run ./potion to restore health
• Run ./sword to equip your weapon
• Defeat the armoury guardian
• Proceed to the Chamber

�️ Quest Prerequisites

• Cellar side-quest complete
• Comfortable with ls -F, cat, and file navigation

⚡ Command Cheatsheet

Command	What It Does
ls -l	Long listing — shows permissions, owner, size
chmod +x file	Add execute permission for everyone
chmod 755 file	rwxr-xr-x — owner can all; others can read+execute
chmod 644 file	rw-r--r-- — owner can read+write; others read only
./script	Execute a script in the current directory

Permission String Decoder

-rwxr-xr-x
│└──┘└──┘└──┘
│ u   g   o
│ user group others
└── file type: - = regular, d = dir, l = link

Each group: r = read (4), w = write (2), x = execute (1)

Octal shorthand: 755 = rwx r-x r-x, 644 = rw- r-- r--

🗺️ Walkthrough

Step 1 — Inspect the armoury

ls -l
# -rw-r--r-- 1 user group  512 Jan 01 potion
# -rw-r--r-- 1 user group 1024 Jan 01 sword
# -rwxr-xr-x 1 user group  256 Jan 01 guardian*

potion and sword lack the x bit — they are not yet executable. You cannot run them.

Step 2 — Try running a locked script

./potion
# bash: ./potion: Permission denied

This is the expected result. Now fix it.

Step 3 — Grant execute permission

chmod +x potion
chmod +x sword
ls -l potion sword
# -rwxr-xr-x 1 user group 512 Jan 01 potion*
# -rwxr-xr-x 1 user group 1024 Jan 01 sword*

Step 4 — Drink the potion

./potion
# HP restored: 50 → 100

Step 5 — Pick up the sword

./sword
# Sword of Echoes added to inventory.

Step 6 — Face the guardian

./guardian
# A stone golem steps forward...
# You raise your sword...
# [combat sequence]

With the sword equipped, you should win. Health permitting, the guardian falls and the door to the Chamber opens.

💡 Understanding Octal Permissions

Octal	Symbolic	Who Can Do What
777	rwxrwxrwx	Everyone can read, write, execute ⚠️
755	rwxr-xr-x	Owner: all; others: read + execute ✅
644	rw-r--r--	Owner: read + write; others: read only ✅
600	rw-------	Owner only — private files 🔒
400	r--------	Read-only, even for owner

Security note: Never use chmod 777 on scripts or sensitive files. Use 755 for scripts and 644 for data.

💡 Common Pitfalls

Problem	Cause	Fix
Permission denied after chmod	Not the file owner	Use ls -l to check owner
Script does nothing	Missing shebang line	Add #!/usr/bin/env bash as line 1
No such file: ./sword	Wrong directory	pwd and ls first
Health still low after potion	Bug in game version	Run ./setup.sh --repair

✅ Validation

• You can read a permission string like rwxr-xr-- without looking it up
• You understand why ./ is needed to run a script
• You ran both ./potion and ./sword successfully
• The guardian is defeated and the Chamber door is open

➡️ Next Steps

• Continue main line → Chamber
• Explore other branches → Chapel · Vault · Scrap
• Back to hub → Bashcrawl Hub

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📚 External Resources

Continue your terminal adventure with these resources:

• Bashcrawl Web Demo — Play in your browser, no installation required
• Bashcrawl on GitHub — Source code, setup, and open contributions
• GNU Bash Manual — Official Bash reference for brave heroes
• IT-Journey Bashcrawl Hub — Full quest series and walkthroughs
• chmod Calculator — Permission wizard for every adventurer

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Sword in hand, potion consumed. The Chamber awaits. ⚔️