As you're reading from the commandline, you'll probably want either a way to warn of invalid keys or, perhaps, ignore them. The following does the latter.
A valid list of keys:
$ perl -Mstrict -Mwarnings -E '
my %x = ( a => { b => { d => 4, e => 5 }, c => 3 } );
my $y = \%x;
for (split /\// => $ARGV[0]) {
last unless ref $y;
$y = $y->{$_};
}
say $y if defined $y;
' a/b/e
5
A partially valid list of keys:
$ perl -Mstrict -Mwarnings -E '
my %x = ( a => { b => { d => 4, e => 5 }, c => 3 } );
my $y = \%x;
for (split /\// => $ARGV[0]) {
last unless ref $y;
$y = $y->{$_};
}
say $y if defined $y;
' a/c/e
3
An invalid list of keys:
$ perl -Mstrict -Mwarnings -E '
my %x = ( a => { b => { d => 4, e => 5 }, c => 3 } );
my $y = \%x;
for (split /\// => $ARGV[0]) {
last unless ref $y;
$y = $y->{$_};
}
say $y if defined $y;
' a/d/e
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