>>>>> "Glenn" == Glenn Becker < burningc%40sdf.lonestar.org">burningc
sdf.lonestar.org> writes:
>> This is really dangerous.... don't do this. Don't use $1 unless
>>; you've also checked that the match has succeeded.
Glenn> Would this be a reasonable place to use "eval" -- say, wrap the two
Glenn> lines above in an "eval" block? like the following
Glenn> eval { /:s+(.*tgz$)/;
Glenn> push packages, $1 };
Glenn> print "No match occurred!n:$" if $;
No, it won't throw an exception if it doesn't match. Just follow the
guidelines. Use it in a conditional if you *expect* it not to match
sometimes. Use it with "or die" if you *never* expect it not to match.
Glenn> Is the danger of using $1 that, if the match does not succeed, you are
Glenn> accessing a "left-over" $1 from another match?
Yes. Or just garbage.... after all, even if $1 was undef on a non-match, your
code would be wrong, because it would push undef into packages, still ruining
the algorithm.
--
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