Dan Muey wrote:
>
> I read in an earlier email that some people put _ in front
> of variables/function/etc to show that they are "important
> and should be handled by the program only" and it
> said that some "modules enforce this"
Hi Dan.
This is historical stuff, and ugly too. When there was no proper
protection against invading foreign namespaces, people decided
to use 'unlikely' prefixes to their variable names to try to
stop them being used elsewhere. DEC (now Compaq), for instance,
decided to use dollar and double-dollar as prefixes for their
operating-system variables.
Perl is different in that you can't write, say, an interrupt
handler, which interfaces directly with the system. But
namespaces do exist (as packages) and there's no way that you
can prevent one package's software accessing another's.
Lexical variables are another matter, as they don't belong to a
given package but exist globally as long as there is a reference
to them. In my opinion this is a bit of a hack, but access can
be limited by creating data that is accessible only by
reference, so that code can reach that data only if it has been
given a reference to it.
All this is independent of the name of the variable, which can
be created with any name you like. This program creates a scalar
with the name "main::~" and prints it successfully.
no strict;
${"\x7E"} = 76;
print ${"main::~"}, "\n";
I can't hope that this will help, as it will probably raise more
questions than answers!
Cheers,
Rob
--
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
