Re: Re: Re: Parse out the extension of a filename

According to everything I have read on PM, the use of rindex() and substr() is a poor way to do this task.

What the...? Can anyone second that (with examples and vivid explanation please)?
I kind of refuse to believe this job should not be done with substr and rindex.

Its just a code snippet....one that works, no less!

One that prints data to the screen, even when not debugging. Not quite useable in most circumstances.
Besides, it doesn't work with all valid filenames:

parse_out_extension 'foo.b(ar';
parse_out_extension 'foo.**';
[download]

No, using arrays and several iterations, printing useless text and not escaping is not a better solution than a pure regex one.
Substr+rindex is the best solution for this, followed by a substitution, but "solutions" like yours are, imho, out of the question.

No offense meant.

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W5kIHBhY2soKS4gQnV0IGRvIHlvdS
ByZWNvZ25pc2UgQmFzZTY0IHdoZW4
geW91IHNlZSBpdD8gIC0tIEp1ZXJk

Comment on Re: Re: Re: Parse out the extension of a filename - return base of filename. Download Code

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Re: Re: Re: Re: Parse out the extension of a filename - return base of filename. by blakem (Monsignor) on Mar 13, 2002 at 19:07 UTC
I can't speak intelligently on the index/regex issue (they are both plenty fast for me....), but the first time I saw it mentioned here on PM was in this comment by merlyn. -Blake	[reply]
Re: Re: Re: Re: Parse out the extension of a filename - return base of filename. by demerphq (Chancellor) on Mar 27, 2002 at 09:55 UTC
According to everything I have read on PM, the use of rindex() and substr() is a poor way to do this task. What the...? Can anyone second that To a certain degree I can second that. Using rindex and index can cause issues. Consider if you have directories with dots in em? Consider if you have multiple extensions, eg File.pl.bak. And for using rindex and index for other aspects of path parsing is also bad especially when you consider the the various path delimiters, and portability issues. Actually it was the use of rindex that caused a script here to behave very strangely just the other day. BTW, you and snafu might like to have a look at one of my earlier posts (and the thread its in) for some interesting discussion about parsing filenames/urls with a regex. Yves / DeMerphq --- Writing a good benchmark isnt as easy as it might look.	[reply]
Re: Re: Re: Re: Parse out the extension of a filename - return base of filename. by snafu (Chaplain) on Mar 13, 2002 at 14:05 UTC
I can't find the nodes that I read where it is suggested to not use those functions. I promise I read those suggestions, though, which is the only reason why I didn't use those functions. Im not sure what data you are talking about that prints to the screen. I don't get any such data, just the return from the function if I print it. I see your point as far as my "solution" (heh, gotta quote it since you are right) is concerned. I need to go back to the drawing board. I asked for comments, I got comments. I feel like I gotta flogging, though. :) _ _ _ _ _ _ _ _ _ _ - Jim Insert clever comment here...	[reply]
Re: Re: Re: Re: Re: Parse out the extension of a filename - return base of filename. by Juerd (Abbot) on Mar 13, 2002 at 14:50 UTC
Im not sure what data you are talking about that prints to the screen. I don't get any such data, just the return from the function if I print it. Here's a part of your original post, before you updated it and removed the print statements: `print "\n-----------\n"; print "There are ". scalar @pieces . " elements in \@pieces from ". "filename: $file\n"; my $c = 0; for ( @pieces ) { print "element ", ++$c, ": $_\n"; } print "-----------\n";` [download] In case your memory has failed you. U28geW91IGNhbiBhbGwgcm90MTMgY W5kIHBhY2soKS4gQnV0IGRvIHlvdS ByZWNvZ25pc2UgQmFzZTY0IHdoZW4 geW91IHNlZSBpdD8gIC0tIEp1ZXJk	[reply] [d/l]