Executiong OS commands through a client facing application
PHP may use the exec, system, shell_exec, passthru, or popen
Eg.
<?php
if (isset($_GET['filename'])) {
system("touch /tmp/" . $_GET['filename'] . ".pdf");
}
?>NodeJS, a developer may use child_process.exec or `child_process.spawn
Eg.
app.get("/createfile", function(req, res){
child_process.exec(`touch /tmp/${req.query.filename}.txt`);
})