Choose Which Version of a Program Runs by Default with update-alternatives

Note#200

notes
Published

2026-03-10

Debian’s update-alternatives manages symlinks in /etc/alternatives/ so that several programs providing the same functionality (e.g., php, java) can coexist, and you pick which one the generic name points to.

Register an Alternative

update-alternatives --install /usr/bin/php php /usr/bin/php8.2 82
update-alternatives --install /usr/bin/php php /usr/bin/php8.3 83

The last number is the priority. Highest priority wins in auto mode.

Switch

# Interactive picker
update-alternatives --config php

# Or set it directly
update-alternatives --set java /usr/lib/jvm/java-21-openjdk-amd64/bin/java

Inspect

# Show current choice and all registered alternatives
update-alternatives --display php

# List all managed groups
update-alternatives --get-selections

Remove

update-alternatives --remove php /usr/bin/php8.2

References

  • man update-alternatives