need Help with Perl matching!!

[JMeng]

Hi I have the following text that I would like to extract the numerical data from:

Statistics for all 1D-facet surfaces:
Surface area (input units ^1) = 1.1111111111111111
Surface area (lambda^1) = 1.1111111111111111
Facets/lambda**1:
Min = 123.1111111111111
Max = 111.1111111111111
Ave = 111.1111111111111
Edges/lambda:
Min = 4.111111111111111
Max = 11.11111111111111
Ave = 1.111111111111111
Facet aspect ratios:
Min = 5.111111111111111
Max = 1.111111111111111
Ave = 1.111111111111111


and this is the part of my code that doesn't do what I was intending to do, which is to extra the numbers from Min, Max, and Ave:

if (my ($FLMin) = /\s*Edges\/lambda:\s*Min =\n\s*(\d+[.]\d+)/s) {print "$FLMin\n";}

I believe iit's just a simple syntax issue but I couldn't figure out where goes wrong. Is there anyone that can help?

 

[brigmar]

First glance:

You need to make it non-greedy.

Your \s* matches are by default greedy, and will match the largest match they can.

So your original will match to 'Edges/lambda' as expected, but the 'Min =' part will match to the last 'Min = ' (the one in facet aspect ratios), and the number will match to the very last number (the ave in facet aspect ratios).

A '?' makes a match non-greedy.

 /\s*Edges\/lambda:\[b]s*?[/b]Min =\n[b]\s*?[/b](\d+[.]\d+)/s

 

[JMeng]

Oh sorry I put the \n in the wrong place.

So the correct code is:

/\s*Edges\/lambda:\n\s*?Min =\s*?(\d+[.]\d+)/s

But what about the first \s*? Why doesn't it need a "?" too?

 

[KevinADC]

Your \s* matches are by default greedy, and will match the largest match they can.

\s* is technically not greedy. ".*" is greedy because it matches as much as possible of anything. \s* only matches as many spaces as necessary.

This line might not be correct:

if (my ($FLMin) = /\s*Edges\/lambda:\s*Min =\n\s*(\d+[.]\d+)/s) {print "$FLMin\n";}

You have used "=", the assignment operator, instead of the regexp binding operator "=~". Using "=" will work only in a special circumstance. It will work if the text is in the system scalar $_ in which case the above line is the same as:

if (my ($FLMin) = $_ =~ /\s*Edges\/lambda:\s*Min =\n\s*(\d+[.]\d+)/s) {print "$FLMin\n";}

the problem is the \n after the "=" in the search pattern. Should be:

if (my ($FLMin) = /\s*Edges\/lambda:\s*Min =\s*(\d+\.\d+)/s) {print "$FLMin\n";}

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- Kevin, perl coder unexceptional!