if ($filename =~ m/^([a-zA-Z0-9\.\_\-\/\\]+)$/)
{
  $filename = $1
  $x = `foo \"$filename\" | bar | baz`;
}
else
{
  print "The filename you entered contains illegal characters.";
}

[download]
This is now untainted too, if you know something about tainting.

In reply to Re: quoting for backticks by Jaap
in thread quoting for backticks by Anonymous Monk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
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