PHP: Executes a console command and returns success or failure

run_cdm_command.php

<?php

/**
 * Validates a .zip file with unzip
 * @param string $filePath
 * @return boolean
 */
function validate($filePath)
{
    // File is valid
    if (!is_file($filePath)) {
        die('File doesn\'t exists or is invalid');
    }
    
    /* The command redirects the output to /dev/null because
    we don't really need it in this case.
    
    The important part is the "echo $?" that will display an integer greater than zero
    if there was an error in the last command.
    
    If we wanted the actual text representation of the error
    thrown by the command, then we may log the output to a temp file
    and retrieve it after. */
    $cmd = "unzip -qqt '{$filePath}' > /dev/null; echo $?";
    // shell_exec returns the output
    $isInvalid = (int) shell_exec($cmd);
    if ($isInvalid) {
        die("This ZIP file is invalid or has errors");
    }
    
    return true;
}