Yes, they can cause problems if they are passed to the shell improperly quoted and/or improperly escaped. In fact, I suspect there's more bad character than just those you listed. That's why it's bad to execute commands via the shell if you can avoid it. It's better to use the multiple argument form of system or exec instead if possible, since their argument don't need to be quoted or escaped then.

In reply to Re^3: checking for reserved characters by ikegami
in thread checking for reserved characters by Real Perl

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