Re^2: Search a hash case insensitive

This code will catch duplicate IDs that are identical.

#!/usr/bin/perl -w
#<SortPW2.pl> /etc/passwd sort by ID

my $PASSWD="passwd";
my $fpid = open(PFILE, "<$PASSWD") or die "Password File Not Found: $!
+\n";

my %ids;
while (my $line = <PFILE>) {
   @ID = split(/:/, $line);
   my $id = ${ID[0]};
   if ($ids{$id}) {
       print "'$id' is duplicate\n";
   } else {
      $ids{$id} = 1;
   }
}
[download]

I wish also to catch IDs that differ only in case. (ie. root , Root , ROOT) Thanx.

Comment on Re^2: Search a hash case insensitive Download Code

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Re^3: Search a hash case insensitive by kennethk (Abbot) on Apr 06, 2011 at 16:51 UTC
This is tangentially discussed in How can I remove duplicate elements from a list or array?, a perlfaq. You can construct your hash, and output whenever you hit a duplicate: `my %seen; while (my $line = <PFILE>) { @ID = split(/:/, $line); my $id = $ID[0]; if ($seen{lc($id)}++) { print "'$id' is duplicate\n"; } }` [download] Note you had incorrect syntax for accessing a list element. I would also recommend against using variables with the same character sequence but different cases for names.	[reply] [d/l]
Re^3: Search a hash case insensitive by Eliya (Vicar) on Apr 06, 2011 at 16:49 UTC
Just lowercase the `$id` you use for the hash lookup: `my $id = $ID[0]; my $id_lc = lc $id; if ($ids{$id_lc}) { print "'$id' is duplicate\n"; } else { $ids{$id_lc} = 1; }` [download]	[reply] [d/l] [select]