how to use hashes by calling the value in perl - perl

Question

I'm currently writing a script to check the existance of files reside in several directories. I'm writing in hash and plan to assign same numeric number to those directories that need to perform same subroutines. And thus I'll call by the value names. In the other words, those directories match the value will do same subroutine else it will be dump into a list so that it will be print out in summary later. I'm writing the script as below but it seem doesn't perform correctly as mit seem doesn't capture the value at all. May I know where goes wrong here? Note I want to call the hash by value but not key.
my %hashDir = (dirA => 1, dirB => 2, dirC =>3 , dirD => 1, dirE =>2, dirF =>1);
my $key = "";
my $value = "" ;
my $buf ;
my $d = "$basedir/$buf";
while (($key, $value) = each (%hashDir)) {
if (exists $hashDir{'1'}) {
print "test1\n" ;
subroutine1() ;
} elsif (exists $hashDir{'2'}) {
print "ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ" ;
subroutine2() ;
} else {
$missingdir .= "\"$buf\" " ;
print "test3\n" ;
}
}

Answer 1

I don't think you understand how to access elements in a hash. When you do exists $hashDir{'1'}, you're looking to see if '1' is a key in the hash. It is not. I think you want to do:
if ($hashDir{$key} == 1)
or since you already have the value,
if ($value == 1)

Answer 2

Use meaningful names rather than $key/$value.
Use a "dispatch table" to decide what subroutine to call.
#!/usr/bin/perl
use warnings;
use strict;
print "Enter path to top-level directory: ";
chomp(my $basedir = <STDIN>);
chdir $basedir or die "could not cd to '$basedir' $!";
my %hashDir = (
dirA => 1,
dirB => 2,
dirC => 3,
dirD => 1,
dirE => 2,
dirF => 1,
);
my %dispatch = (
1 => \&subroutine1,
2 => \&subroutine2,
3 => \&subroutine3,
);
my #missing;
while ( my($dir, $group) = each (%hashDir) ){
if (-d $dir) {
$dispatch{$group}->($dir);
}
else {
push #missing, $dir;
}
}
print 'Missing dirs: ', join(', ', #missing), "\n" if #missing;
sub subroutine1 { warn "subroutine1() got called for $_[0] directory\n" }
sub subroutine2 { warn "subroutine2() got called for $_[0] directory\n" }
sub subroutine3 { warn "subroutine3() got called for $_[0] directory\n" }