bash: ./script.sh: Permission denied
PermissionError: [Errno 13] Permission denied
EACCES: permission denied, open '/usr/local/lib/node_modules'

“Permission denied” means your current user account doesn’t have the required access level (read, write, or execute) for the file, directory, or operation you’re attempting.

How Linux/Mac permissions work

Every file and directory has three permission sets:

• Owner — the user who created it
• Group — users in the file’s group
• Others — everyone else

Each set has three permissions:

• r (read) — view file contents or list directory
• w (write) — modify file or create/delete files in directory
• x (execute) — run as program or enter directory

# Example: ls -la output
-rwxr-xr-- 1 alice developers 4096 May 15 script.sh
│├─┤├─┤├─┤
│ │   │   └── Others: read only
│ │   └────── Group: read + execute
│ └────────── Owner: read + write + execute
└──────────── File type (- = file, d = directory)

Fix 1: Make a script executable

The most common case — you created a script but forgot to add execute permission.

# ❌ Script isn't executable
./deploy.sh  # Permission denied

# ✅ Add execute permission for the owner
chmod +x deploy.sh
./deploy.sh  # Works

# Or be specific about who gets execute
chmod u+x deploy.sh   # Only owner
chmod a+x deploy.sh   # Everyone

Why this happens: When you create a file (with a text editor, touch, or download), it doesn’t get execute permission by default. This is a security feature — you must explicitly mark files as executable.

Fix 2: Fix file ownership

If a file is owned by root or another user, you can’t modify it even if the permissions look right.

# Check ownership
ls -la config.yml
# -rw-r--r-- 1 root root 256 May 15 config.yml
#              ^^^^ owned by root!

# Change ownership to your user
sudo chown $USER:$USER config.yml

# Recursively for a directory
sudo chown -R $USER:$USER ./my-project/

# Change only the group
sudo chgrp developers shared-folder/

Common cause: Running a command with sudo creates files owned by root. Then your normal user can’t modify them. Avoid sudo unless necessary.

Fix 3: Use sudo correctly

Some operations legitimately require root access — writing to system directories, installing system packages, modifying system config.

# ❌ Direct write to system directory
echo "127.0.0.1 myapp.local" > /etc/hosts  # Permission denied

# ✅ Use sudo with tee (preserves redirect)
echo "127.0.0.1 myapp.local" | sudo tee -a /etc/hosts

# ❌ Don't do this — creates root-owned files in your project
sudo npm install
sudo pip install

# ✅ Fix the underlying permission issue instead

Rule: If you need sudo for development tools (npm, pip, docker), the tool is misconfigured. Fix the configuration rather than using sudo as a workaround.

Fix 4: SSH key permissions

SSH is strict about key file permissions. If your private key is readable by others, SSH refuses to use it.

# ❌ Key permissions too open
ssh user@server
# Permissions 0644 for '/home/user/.ssh/id_rsa' are too open.
# It is required that your private key files are NOT accessible by others.

# ✅ Fix SSH directory and key permissions
chmod 700 ~/.ssh              # Directory: owner only
chmod 600 ~/.ssh/id_rsa       # Private key: owner read/write only
chmod 644 ~/.ssh/id_rsa.pub   # Public key: owner read/write, others read
chmod 644 ~/.ssh/authorized_keys
chmod 644 ~/.ssh/known_hosts
chmod 600 ~/.ssh/config       # SSH config: owner only

Fix 5: npm/Node.js EACCES errors

# ❌ Global install fails
npm install -g typescript
# EACCES: permission denied, mkdir '/usr/local/lib/node_modules/typescript'

Don’t use sudo npm install -g — it creates root-owned files that cause more problems later.

Option A: Change npm’s default directory:

mkdir -p ~/.npm-global
npm config set prefix '~/.npm-global'
echo 'export PATH=~/.npm-global/bin:$PATH' >> ~/.bashrc  # or ~/.zshrc
source ~/.bashrc
npm install -g typescript  # Works without sudo

Option B: Use nvm (recommended):

# nvm installs Node in your home directory — no permission issues
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.0/install.sh | bash
nvm install --lts
npm install -g typescript  # Works without sudo

Fix 6: Docker permission denied

# ❌ Can't run docker commands
docker ps
# permission denied while trying to connect to the Docker daemon socket

# ✅ Add your user to the docker group
sudo usermod -aG docker $USER

# IMPORTANT: Log out and back in (or restart) for the group change to take effect
# Verify:
groups  # Should show 'docker' in the list

On macOS: Docker Desktop handles permissions automatically. If you get permission errors, restart Docker Desktop.

Fix 7: Python PermissionError

# ❌ Writing to a directory you don't own
with open('/var/log/myapp.log', 'w') as f:  # PermissionError

# ✅ Write to a user-accessible location
with open(os.path.expanduser('~/myapp.log'), 'w') as f:

# ✅ Or create the directory with proper permissions first
os.makedirs('/var/log/myapp', exist_ok=True)  # Needs sudo once

For pip install errors:

# ❌ System Python is protected
pip install requests  # Permission denied

# ✅ Use a virtual environment
python -m venv .venv
source .venv/bin/activate
pip install requests  # Works — installs in .venv/

Fix 8: Git permission denied

# ❌ Can't push to remote
git push origin main
# Permission denied (publickey)

# Check if your SSH key is loaded
ssh-add -l

# If empty, add your key
ssh-add ~/.ssh/id_rsa

# Test the connection
ssh -T git@github.com

See Git Permission Denied Publickey — Fix for a complete guide.

Permission numbers cheat sheet

Number	Permission	Meaning
7	rwx	Read + Write + Execute
6	rw-	Read + Write
5	r-x	Read + Execute
4	r—	Read only
0	---	No access

Common combinations:

chmod 755 directory/   # Owner: full, Others: read+execute (standard for directories)
chmod 644 file.txt     # Owner: read+write, Others: read (standard for files)
chmod 600 secret.key   # Owner only (private keys, credentials)
chmod 777 file         # ❌ NEVER do this — everyone can read/write/execute

FAQ

Should I use chmod 777 to fix permission errors?

No. chmod 777 gives everyone full access, which is a security risk. It’s the equivalent of leaving your front door open. Find the specific permission needed and grant only that.

Why do I get “Operation not permitted” instead of “Permission denied”?

“Operation not permitted” (EPERM) means even root can’t do it — the operation is blocked by the system (e.g., modifying immutable files, SIP on macOS, or SELinux). “Permission denied” (EACCES) means your user lacks the required permission but root could do it.

How do I fix permissions on macOS with SIP?

System Integrity Protection prevents modifying /usr/bin, /System, and other protected paths — even with sudo. You can’t disable it without booting into Recovery Mode. Instead, install tools to /usr/local/bin (Homebrew does this automatically).

What’s the difference between chmod and chown?

chmod changes what actions are allowed (read/write/execute). chown changes who owns the file. You might need both: chown to make yourself the owner, then chmod to set the right permissions.

Related fixes

• Linux Permission Denied Bash — Fix
• EACCES Permission Denied npm — Fix
• Docker Permission Denied — Fix
• Git Permission Denied Publickey — Fix
• Linux Command Not Found — Fix
• Bash Cheat Sheet