How can PHP be used to handle error return values when executing Linux commands like "wget" and "mv" using the "exec" function?

When executing Linux commands like "wget" and "mv" using the PHP "exec" function, it's important to handle error return values to ensure the command executed successfully. This can be achieved by capturing the return value of the "exec" function and checking if it is equal to 0, which indicates success. If the return value is not 0, it means there was an error during command execution.

// Execute wget command
exec("wget http://example.com/file.zip", $output, $return);

// Check if return value is 0 (success)
if($return === 0){
    echo "wget command executed successfully!";
} else {
    echo "Error executing wget command!";
}

// Execute mv command
exec("mv file.zip /path/to/destination/", $output, $return);

// Check if return value is 0 (success)
if($return === 0){
    echo "mv command executed successfully!";
} else {
    echo "Error executing mv command!";
}