Re^3: write and read the same file not display the output

Hello ulaksh, Im guessing youve commented out your print "$_"; on purpose there. Anyway your getting yelled at because when the regex doesnt make a match, $a is not getting defined at all, so it is still undefined. You then try to use it on the next line print $a; You cant print $a because it has no value. It is undefined at the moment. This is also the reason your not getting anything printed to screen. maybe you can try this instead? :

print $1 if /^($name)$/;
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Re^4: write and read the same file not display the output by Kenosis (Priest) on Sep 05, 2012 at 02:07 UTC
Good eye, Rudolf! Did you mean: `print $1 if /^($name)$/;` [download]	[reply] [d/l]
Re^5: write and read the same file not display the output by Rudolf (Pilgrim) on Sep 05, 2012 at 03:08 UTC
Hey thanks for the nice reply, but I was not aware of a difference in the regex with the parentheses (though I updated my post): It would be good if you can point it out for me, always up for learning more Perl ! :-) `print $1 if /^$name$/; #or print $1 if /^($name)$/;` [download]	[reply] [d/l]
Re^6: write and read the same file not display the output by Kenosis (Priest) on Sep 05, 2012 at 04:53 UTC
`$1` is initialized via regex captures which use parentheses. For example, in the following: `my $string = 'Frank'; my $name = 'Frank'; print $1 if $string =~ /^$name$/; print $1 if $string =~ /^($name)$/;` [download] The first `print` statement produces: `Use of uninitialized value $1 in...` [download] Whereas, the second `print` shows the value in `$1`: `Frank` [download]	[reply] [d/l] [select]
Re^7: write and read the same file not display the output by Rudolf (Pilgrim) on Sep 05, 2012 at 13:09 UTC