difference between "*." and "." operators

vaibhav4947 has asked for the wisdom of the Perl Monks concerning the following question:

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Re: difference between "*." and "." operators by svenXY (Deacon) on Oct 11, 2007 at 10:23 UTC
Hi, not sure I understand what you want... This is how I interpret your code (pls. use code tags by the way): #!/usr/bin/perl use strict; use warnings; my $string = "abcABC123ABCabc"; # the following is using shell commands # to do something perl can do much better... echo `expr match "$string" 'abc[A-Z].2'` ; echo `expr match "$string" 'abc[A-Z]2'` ; [download] As said - not sure what your intention is. To test a regex, you'd use something like: `#!/usr/bin/perl use strict; use warnings; my $string = "abcABC123ABCabc"; print "Regex1: ", $string =~ /abc[A-Z].2/, "\n" ; print "Regex2: ", $string =~ /abc[A-Z]2/, "\n";` [download] Result: `Regex1: 1 Regex2:` [download] Reason: The first matches any number of uppercase characters, followed by 1 character then followed by a 2 (this regex matched once in the string, therefore 1). The second matches any number of A-Z followed by a 2 - as there is a 1 inbetween, it doesn't match. Maybe you look after .* which will match any number of any character??? Regards, svenXY	[reply] [d/l] [select]
Re: difference between "*." and "." operators by jhourcle (Prior) on Oct 11, 2007 at 10:57 UTC
echo `expr match "$string" 'abcA-Z.2'` You're using backticks, which is causing perl to call a shell. `expr` is a shell function, not a perl function. You'll want to run '`man expr`' on your system to get the documentation for that command. update:*For some reason my brain wasn't working this morning -- you're calling `echo`, which isn't a perl command, either. I have a feeling that your whole thing is shell, not Perl.	[reply] [d/l] [select]
Re^2: difference between "*." and "." operators by svenXY (Deacon) on Oct 15, 2007 at 06:32 UTC
++jhourcle - I believe you are right - that was no Perl at all in the OP. At least we explained the Perl-way of doing this now ;-) Regards, svenXY	[reply]
Re: difference between "*." and "." operators by johngg (Canon) on Oct 11, 2007 at 10:33 UTC
It may help you to study the tutorial and there is also the documentation available for deeper explanations. Cheers, JohnGG	[reply]
Re: difference between "*." and "." operators by shmem (Chancellor) on Oct 11, 2007 at 14:39 UTC
how . and * operators work* None of them is an operator. Both are metacharacters. One is a quantifier - `` - match zero ore more times the preceeding character. The other is an alias - `.` - match any* character. Read perlre where these are covered. Speaking of the meaning of `*.` is like speaking of the meaning of "od mo" in the expression "Good morning". --shmem _($_=" "x(1<<5)."?\n".q·/)Oo. G°\ / /\_¯/(q / ---------------------------- \__(m.====·.(_("always off the crowd"))."· ");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}	[reply] [d/l] [select]