Hi folks, happy new year to everyone. )
John, you're right, of course. ) The filenames in nested directories could
well overlap, and using $File::Find::name would be safer.
Didn't think of that as a big problem, though, as original script (with
'opendir') ignored all the nested folders overall.
Jonathan, no, you don't have to store the filenames as array: complete
pathnames of the file can't be repeated.
It'll be sufficient just to change this line:
$filedata{$_} = [$filesize, $filemd5]
for
$filedata{$File::Find::name} = [$filesize, $filemd5]
(and replace catfile in the writing block as well, as %filedata keys will
now be the whole filenames themselves).
On sorting: cmp and <=> is not the same: former compares strings, latter -
numbers.
So, for example, 'abc' cmp 'def' gives you -1, but 'abc' <=> 'def' gives 0
(and warnings about non-numeric args as well).
It's nice to know the difference, but... do you really need to sort the
output in your script? What output? )
It makes no difference in what order your .md5 files will be created,
right? And you don't need to print the list of files processed
(as I did in my test script, that's why the ordering was ever mentioned).
As for $_, the problem John mentioned is logical, not 'perlical': as $_
variable is assigned a filename processed within File::Find target sub,
and files in different directories could have the same names (but not full
names, with absolute path attached), it may cause a bit of confusion when
they DO have the same names. )
Generally speaking, $_ usage is for comfort and speed (yes, thinking of it
as of 'it' word is right )). Of course, you can reassign it, but it'll make
your scripts bigger (sometimes _much_ bigger) without adding much clarity,
in my opinion. But that, again, is a matter of taste.
For me, I use $_ almost every time I process shallow collections (hashes or
arrays, doesn't matter). When two-level (or more complex) data structure is
processed, it's usually required to use a temporary variable - but even
then inner layers can be iterated with $_ easily.
-- iD
