Re^2: File ext number

Your match doesn't match when readdir returns .

Are you saying that the dot (.) directory somehow makes it past the grep {-f} filter in the OP's code? I freely admit I have no idea what that whole line does in the OP's code, but it would be surprising to me if . made it past the filter.

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Re^3: File ext number by ikegami (Patriarch) on Mar 19, 2010 at 23:54 UTC
Are you saying that the dot (.) directory somehow makes it past the grep {-f} filter in the OP's code? I guess I was without realizing it. Obviously, that's not true and my explanation is wrong. Take two: `$ext{$1} += (m/([^.]+)$/);` [download] means something close to `$ext{$1} = $ext{$1} + (m/([^.]+)$/);` [download] Well, actually more like the following, but it doesn't matter for this discussion: `alias $temp = $ext{$1}; $temp = $temp + (m/([^.]+)$/);` [download] Either way, you are relying on Perl evaluating the RHS of the "+=" operator before its LHS, and that's not how Perl operates. In fact, Perl doesn't document how it operates in this circumstance, and that's the reason it's generally a no-no to change and use the same variable in the same expression. Even though my earlier explanation was wrong, the solutions I posted still avoid the problem. Update: Improved phrasing by inlining footnotes.	[reply] [d/l] [select]

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Re^3: File ext number
by ikegami (Patriarch) on Mar 19, 2010 at 23:54 UTC

Are you saying that the dot (.) directory somehow makes it past the grep {-f} filter in the OP's code?

I guess I was without realizing it. Obviously, that's not true and my explanation is wrong. Take two:

$ext{$1} += (m/([^.]+)$/);
[download]

$ext{$1} = $ext{$1} + (m/([^.]+)$/);
[download]

Well, actually more like the following, but it doesn't matter for this discussion:

alias $temp = $ext{$1};
$temp = $temp + (m/([^.]+)$/);
[download]

Either way, you are relying on Perl evaluating the RHS of the "+=" operator before its LHS, and that's not how Perl operates. In fact, Perl doesn't document how it operates in this circumstance, and that's the reason it's generally a no-no to change and use the same variable in the same expression.

Even though my earlier explanation was wrong, the solutions I posted still avoid the problem.

Update: Improved phrasing by inlining footnotes.

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