http://qs321.pair.com?node_id=687572


in reply to Regular expression * vs +

In addition to moritz' hint, you could look into the matching process by issuing (e.g.):

 ...
 my $txt = '-UK 123 123-UK 123-UK 123-UK';

 print "|$1|\n" while $txt =~ /((?:\d+-UK\W?)*)/g;
 ...

[download]

Regards

mwa

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Re^2: Regular expression * vs +
by ww (Archbishop) on May 20, 2008 at 11:58 UTC

    Close, but not sure OP wants this (from mwah's example):

    687551.pl syntax OK
perl  687551.pl
||
||
||
||
||
||
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||
|123-UK 123-UK 123-UK|
||

    [download]

    Whereas:

    my $txt = '-UK 123 123-UK 123-UK 123-UK abc-oops!';
print "|$1|\n" while $txt =~ /((?:\d+-UK\s))/g;

    [download]

    produces

    perl  687551.pl
|123-UK |
|123-UK |
|123-UK |

    [download]
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      I think the OP struggled over the difference between

       ...
 my $txt='-UK 123 123-UK 123-UK 123-UK';
 print "|$1| - match until pos:" . pos($txt) . "\n" while $txt=~/((?:\
+d+-UK\W?)+)/g ;
 ...

      [download]

      and

       ...
 my $txt='-UK 123 123-UK 123-UK 123-UK';
 print "|$1| - match until pos:" . pos($txt) . "\n" while $txt=~/((?:\
+d+-UK\W?)*)/g ;
 ...

      [download]

      which is the difference between (expr)+ and (expr)*, the latter matching everywhere and (of course) at 'expr', the former matching only at 'expr'.

      (maybe I misinterpreted his intention)

      Regards

      mwa

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