2.3Changing Permissions

# Make a script executable
chmod +x run-tests.sh

# Give owner full access, group read+execute, others nothing
chmod 750 run-tests.sh
# Owner: rwx (7), Group: r-x (5), Others: --- (0)

# Make a file readable only by the owner (sensitive config)
chmod 600 credentials.json
# Owner: rw- (6), Group: --- (0), Others: --- (0)

# Recursively set permissions on a directory
chmod -R 755 scripts/

# Change owner of test results directory
chown -R qa:dev test-results/
# Now the 'qa' user and 'dev' group own the directory and its contents

Common Permission Scenarios for QA

Scenario	Command	Why
Script won't run	chmod +x script.sh	Script needs execute permission
CI fails with "Permission denied"	chmod 755 scripts/	Runner user lacks permissions
Sensitive file exposed	chmod 600 .env	Restrict access to owner only
Test artifacts not writable	chown -R $(whoami) test-results/	Wrong owner from previous run