How can PHP developers ensure that the correct file paths are passed as parameters to external programs for optimal performance?

To ensure that the correct file paths are passed as parameters to external programs for optimal performance, PHP developers should use absolute paths instead of relative paths. This helps avoid any confusion or errors that may arise due to differences in working directories. Additionally, it is important to properly sanitize and validate user input to prevent any security vulnerabilities.

// Example of passing an absolute file path as a parameter to an external program
$filePath = '/path/to/file.txt';
$command = "external_program $filePath";
exec($command);