in reply to read-only error

The Read only error accurred on line 868 which is : 
my %uniq;

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could someone explain to me what the last 3 line is doing line by line?

Thanks,
Paul

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Re^2: read-only error
by grep (Monsignor) on Aug 24, 2006 at 18:31 UTC
    The Read only error accurred on line 868 which is : my %uniq; could someone explain to me what the last 3 line is doing line by line?

    Yes but you have more problems as I stated above; 

    my %uniq;
# create a hash called %uniq

undef @uniq{@dist_list};
# takes the array @dist_list as keys to create in %uniq
# each with the value undef.
# Since you can only have 1 unique key in a hash this
# has the effect of filtering out repeats
#ex.
#
# %uniq = {
#          '1 2 3' => undef,
#          '4 5 6' => undef,
#          '5 6 7' => undef
#        };


@dist_list = keys %uniq;
# this pulls the keys from %uniq and assings them to @dist_list

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    So this code is not a problem - you need to fix the other problems first.


    grep
    Mynd you, mønk bites Kan be pretti nasti...
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Re^2: read-only error
by ikegami (Patriarch) on Aug 24, 2006 at 18:32 UTC

    Sometimes, the line number in error messages are off by a bit. I think that's the case here.

    undef @uniq{@dist_list};
    is equivalent or similar to
    $uniq{$_} = undef for @dist_list;

    Together, the three lines remove duplicate items in @dist_list, assuming @dist_list only contains strings. (Anything in @dist_list which isn't a string is first converted to a string.) The order of the items in @dist_list is not guaranteed to remain unchanged.

    By the way, it's <code>..</code> (or <c>..</c>), not <code>..<code/>.

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