in reply to RE: RE: Selective substitution: not in Perl?
in thread Selective substitution: not in Perl?

The .* is greedy, as far as I can see that will always replace ithe last match if you have more than the number you need. 
my string = "foo_a_foo_b_foo_c_foo_d_foo_e_foo_f_foo"
my $pattern = "foo"
my $better = "bar"
my $n = 1;

$string =~ s/^(($pattern.*){$n})$pattern/$1$better/;

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would give: 
"foo_a_foo_b_foo_c_foo_d_foo_e_foo_f_bar"

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not 
"foo_a_bar_b_foo_c_foo_d_foo_e_foo_f_foo"

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Nuance

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RE: RE: RE: RE: Selective substitution: not in Perl?
by davorg (Chancellor) on Aug 16, 2000 at 14:51 UTC

    You're absolutely right, of course. Now I remember why I didn't post that solution in the first place :(

    Update:

    On thinking about it further, I realise that: 

    $string =~ s/^(($pattern.*?){$n})$pattern/$1$better/;

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    will probably do the trick.

    --
    <http://www.dave.org.uk>

    European Perl Conference - Sept 22/24 2000, ICA, London
    <http://www.yapc.org/Europe/>
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