IntroToLinux

3. Ownership with chown and chgrp

Changing File Ownership

chown Command:

# Change owner only
chown newowner file.txt

# Change owner and group
chown newowner:newgroup file.txt
chown newowner. file.txt          # Use owner's primary group

# Change recursively
chown -R newowner:newgroup directory/

# Change only if current owner matches
chown --from=oldowner newowner file.txt

chgrp Command:

# Change group only
chgrp newgroup file.txt

# Change recursively
chgrp -R newgroup directory/

# Use reference file's group
chgrp --reference=reference.txt target.txt

Practical Ownership Examples:

# Web server files
sudo chown -R www-data:www-data /var/www/html/

# User's files (fixing ownership issues)
sudo chown -R user:user /home/user/

# Shared project directory
sudo chown -R :developers /opt/project/
sudo chmod -R g+w /opt/project/

# System files
sudo chown root:root /etc/passwd
sudo chmod 644 /etc/passwd

# Log files
sudo chown syslog:adm /var/log/syslog
sudo chmod 640 /var/log/syslog

Next: → Special Permission Bits
Previous: ← The Chmod Command
Lesson Home: ↑ Lesson 10: Permissions Course Home: ⌂ Introduction to Linux