! /usr/local/bin/perl   -w

#Skript searches for filenames in a spec. directory
#referring to a text file which contains a list of Ids

$dir = $ARGV[0]; 

#Scan a directory and write filenames into an array
opendir (SOURCE, $dir)or die "Cannot open dir: $!\n";
         foreach $file (readdir SOURCE) {
         push (@dirFile, $file);     #more than 6000 filenames
         }
closedir SOURCE;

#Open a filehandle and read a list from a text file
$ref = "indexDS.txt";
open(FH, $ref) or die "Cannot open file: \n$!";
@ds = <FH>;
close (FH);

chomp @dirFile;
chomp @ds;		
		
#Test: it works if array is defined like this:
#@ds = ("I C 7702", "I C 7710", "I C 7713");	

#Search for element of @ds as regex in @dirFile
foreach $line (@ds) {
        @result = grep (/$line/, @dirFile); 
		foreach (@result) {
		print "$_\n";
		}
}