Hi Monks: I get an error that says "readdir() attempted on invalid dirhandle DH" from the code below, so what do I do, Thanks, Chet: 
#!/usr/bin/perl
use strict;
use warnings;

my $outputfile ="Test_PDB_ID_list.txt";
my $four_char_PDB_ID='';
open (PDB_IDs,">", "$outputfile");
my $PDB_ID= '';

my $dir_to_process= '';
print "What is the directory to process?";

$dir_to_process = <STDIN>;
#$dir_to_process = "Targets-IonChannel";-if I used this #line it would
+ work
#open the folder
unless (opendir(DH, $dir_to_process)){
    print "Cannot open folder $dir_to_process!\n";
    
}
print "$dir_to_process\n";
foreach $PDB_ID (readdir DH){
    $four_char_PDB_ID =substr($PDB_ID,0,4);
    print PDB_IDs "$four_char_PDB_ID\n";
    print "$four_char_PDB_ID \n";
    
    
};

exit;

[download]

What is the directory to process?

Targets-IonChannel

Cannot open folder

Targets-IonChannel

!

Targets-IonChannel

readdir() attempted on invalid dirhandle DH at C:\Users\cseligman\Documents\Eclipseworkspace\DrugTargets\GetPDBnames-1.pl line 21, <STDIN> line 1.

In reply to Get a DH from <STDIN>? by cseligman

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