cd /path/to/your/project

3. Determine Composer Path

To find the path of the Composer executable, use:

which composer

This command will return the path where Composer is installed, like /usr/local/bin/composer.

4. Run Composer with the Desired PHP Version

Use the path to the PHP executable when running Composer:

/usr/bin/php7.1 $(which composer) install

5. Repeat for Different Projects

For each project that requires a different PHP version, repeat the process with the corresponding PHP executable. For instance, for PHP 8.0:

Conclusion

Using Composer with various PHP versions is straightforward once you know the paths to your PHP executables and the Composer binary. This approach provides the flexibility to manage dependencies in a multi-PHP environment effectively, aligning each project with its specific PHP version requirements.