Python code to Perl
<p>I have a piece of python code, that I need to convert it to perl, but unfortunately I am not good in perl, so sorry if the question is simple.
I would like to check STDOUT and STDERR for a specific word. Here is the python code:</p>

<pre><code>p = subprocess.Popen("bmod -b " + beginTime + " " + job_id + "; exit 1;", 
stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)

while p.poll() is None:
    err = p.stderr.readline().decode('utf_8')
    out = p.stdout.readline().decode('utf_8')
    if "changed" in err or "changed" in out:
        subprocess.Popen("echo rescheduling was successful!", shell=True)
os._exit(0)
</code></pre>

<p>I read some documentations and open3 function may work here, but for p.poll() part I am not sure what to use.</p>