A solution using glob to generate the 4-digit numbers, split, sort and join to get only ascending values then grep and a regex to sift out repeating digits. A hash is populated so that any duplicate values go into the same key/value pair and are therefore masked. Finally print the sorted values.

johngg@abouriou ~/perl/Monks $ perl -Mstrict -Mwarnings -E '
my $digs    = q{0,1,2,3,4,5,6,7,8,9};
my $globStr = qq|{$digs}| x 4;
my %combs   =
   map  { $_ => 1 }
   grep { ! m{(.).*\1} }
   map  { join q{}, sort split m{} }
   glob $globStr;
say for sort keys %combs;' | wc -l
210

[download]

I hope this is of interest.

Update: Can be shortened by acting directly on an anonymous hash but there's a warning unless you silence it (which, sadly, makes it not so short again).

johngg@abouriou ~/perl/Monks $ perl -Mstrict -Mwarnings -E '
my $digs    = q{0,1,2,3,4,5,6,7,8,9};
my $globStr = qq|{$digs}| x 4;
say for do {
   no warnings qw{ experimental::autoderef };
   sort keys {
   map  { $_ => 1 }
   grep { ! m{(.).*\1} }
   map  { join q{}, sort split m{} }
   glob $globStr };
   };' | wc -l
210

[download]

Cheers,

JohnGG

In reply to Re: list of four digit lock combinations without repeated digits by johngg
in thread list of four digit lock combinations without repeated digits by Lotus1

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