extracting numbers from a string

rbi has asked for the wisdom of the Perl Monks concerning the following question:

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Re: extracting numbers from a string by jeroenes (Priest) on Feb 07, 2001 at 18:26 UTC
This is really basic knowledge, and I hope you can gain some understanding by reading the docs. There are various methods, depending on what you like (or want to learn). I suggest you take a look at perlre and unpack, you can use both. Or use substr, like modred says, it's faster than m//. But to give you a start, try this: `($x,$z) = $filename =~ /(\d\d)-(\d\d)/;`for the first two numbers. The others are left as an exercise.... or just fill in modred's regex. Jeroen "We are not alone"(FZ) Update: Thought you might as well have a look at 7 Stages of Regex Users	[reply] [d/l]
Re: extracting numbers from a string by Albannach (Monsignor) on Feb 07, 2001 at 19:08 UTC
As jeroenes mentioned, TIMTOWTDI, and I favour unpack for cases like this: `$filename = '11-22-2001012004'; ($x,$z,$y,$m,$d,$h) = unpack('a2xa2xa4a2a2a2', $filename)` [download] -- I'd like to be able to assign to an luser	[reply] [d/l]
Re: extracting numbers from a string by modred (Pilgrim) on Feb 07, 2001 at 18:22 UTC
If they are all in fixed positions you can use substr repeatedly to extract the values or you can use a regular expression and assign from the $1-$9 variable. perldoc -f substr perldoc perlre the regular expression code would look something like `$filename='XX-ZZ-YYYYMMDDHH' $filename =~ /^(\d{2})-(\d{2})-(\d{4})(\d{2})(\d{2})(\d{2})$/; # $1 is XX, $2 is ZZ, and so on` [download]	[reply] [d/l]
Re: extracting numbers from a string by kschwab (Vicar) on Feb 07, 2001 at 18:27 UTC
Have a look at perldoc perlre. `#!/usr/bin/perl my($filename)="11-22-2001012004"; my($x,$z,$y,$m,$d,$h)= ($filename=~/(\d\d)-(\d\d)-(\d\d\d\d)(\d\d)(\d\d)(\d\d)/); printf "[%s] [%s] [%s] [%s] [%s] [%s]\n", $x,$z,$y,$m,$d,$h;` [download] Produces: `[11] [22] [2001] [01] [20] [04]` [download]	[reply] [d/l] [select]
Re: extracting numbers from a string by davorg (Chancellor) on Feb 07, 2001 at 18:39 UTC
The easiest way might be something like this: `#!/usr/bin/perl -w use strict; my $data = '12-34-2001020713'; my @nums = $data =~ /\d\d/g; print "@nums\n";` [download] But you end up with the year split between two elements of the array. I suppose it's not too difficult to join them together again. -- <http://www.dave.org.uk> "Perl makes the fun jobs fun and the boring jobs bearable" - me	[reply] [d/l]
Re: extracting numbers from a string by Anonymous Monk on Feb 07, 2001 at 19:32 UTC
thanks you all for the explanations and suggestions for readings. And sorry if the question was a silly one: I've just started this week with Perl... roberto	[reply]