When opendir fails, you should die and examine the error message. 
opendir(DH, $dir_to_process)
    or die "Cannot open $dir_to_process: $!";

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Most likely you just need to chomp your input string 
my $dir_to_process = <STDIN>;
chomp $dir_to_process;

[download]

In reply to Re: Get a DH from <STDIN>? by wind
in thread Get a DH from <STDIN>? by cseligman

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