With 
use strict;

my %hash = map
{
      (split /:/, $_ )[0] => (split /:/, $_ )[2]
}
<DATA>;

print join ",", sort keys %hash; #key1,key2

__DATA__
key1:useless:value1
key2:useless:value2

[download]
I get : 
key1,key2

[download]
The thing is, I do the same thing as your code in mine, two times : the first time, with a first array given to the map function, it works fine ; but the second time, with another array, it "inverts" the keys and the values.

In reply to Re^4: Problem generating a hashtable by Tomtom
in thread Problem generating a hashtable by Tomtom

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