What potential issues can arise when using shell_exec in PHP to execute Java files with specific operators?

When using shell_exec in PHP to execute Java files with specific operators, potential issues can arise due to security vulnerabilities, command injection attacks, and improper handling of user input. To mitigate these risks, it is important to sanitize and validate user input, use escapeshellarg or escapeshellcmd to escape special characters, and restrict the commands that can be executed.

$javaFile = "YourJavaFile.java";
$operator = "+";
$escapedOperator = escapeshellarg($operator);

$command = "java $javaFile $escapedOperator";
$output = shell_exec($command);

echo $output;