Do you know about the ref function? You can use it to tell what kind of data is referenced, affecting how you handle it.
Here's a very quick-and-dirty subroutine show_this() that uses ref to recursively inspect the contents of your hash. As such, it's a primitive replacement for Data::Dumper:
#!/usr/bin/perl -w # use strict; use warnings; use Data::Dumper; my %singleLevelHash = (); my %multiLevelHash = ( 'firstSampleKey' => 'SampleValue', 'secondSampleKey' => { 'secondLevelSampleKey' => { 'thirdLevelSampleKeyOne' => 'thirdLevelSampleValue', 'thirdLevelSampleKeyTwo' => 'thirdLevelSampleValue', 'thirdLevelSampleKeyThree' => 'thirdLevelSampleValue', } } ); # print Dumper \%multiLevelHash; show_this(\%multiLevelHash); # foreach my $firstSampleKey ( sort keys %multiLevelHash ) { # print $firstSampleKey . "\n"; # foreach my $secondLevelSampleKey ( sort keys $multiLevelHash{$fi +rstSampleKey} ) { # print $secondLevelSampleKey . "\n"; # } # } sub show_this { my ($x) = @_; if (ref $x eq "") { printf " Value: '%s'\n", $x; } elsif (ref $x eq 'SCALAR') { printf " SCALAR ref: '%s'\n", $$x; } elsif (ref $x eq 'HASH') { print " HASH ref '$x':\n"; foreach my $key (keys %$x) { my $val = $x->{$key}; print " $key: "; show_this($val); } } elsif (ref $x eq 'ARRAY') { print " ARRAY re '$x':\n"; foreach my $val (@$x) { show_this($val); } } }
Hopefully that gives you an idea how to interpret a HASH ref, differently from a scalar value. Hint -- the solution is in the block:
foreach my $key (keys %$x) { ... }
In reply to Re: How to print a multi-level Hashes of Hashes without the use of a module
by golux
in thread How to print a multi-level Hashes of Hashes and extract parts of it
by thanos1983
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