title: What does 'echo' do within a perl variable declaration?
body: <p>I am working on transcribing an outdated file from perl to python and got caught up with some perl syntax.</p>
  <pre><code>my $jobID = `echo \$JOBID`;
  chomp($jobID);
  unless ($jobID) {
    print &quot;Please specify a job\n&quot;;
    exit;
  } 
  </code></pre>
  <p>Thus far, I have been able to transcribe all of the command-line parsing extremely easily but am very fairly stuck here with what exactly this code is doing (specifically the <strong>echo</strong> within the declaration on line 1).</p>
  <p>Within the perl script cmd-line parsing options - that enables one to set the jobID - it states that &quot;default = $JOBID&quot;. So my assumption is that the first line in this code simply sets this default jobID until one is specified.</p>
  <p>If this is the case why would you need to use echo within the variable default declaration? Is this good practice in perl or am I missing a larger picture?</p>
  <p>I have tried searching low and high for this but can't seem to google ninja my way to anything useful.</p>
  <p>Any help on the 'echo' would be greatly appreciated (or any good reads on this as well)!</p>