use strict;
my $file = '.';
opendir(MYDIR,$file);
my @files = readdir(MYDIR);

foreach $_ (@files)
{
next if($_ =~ m/^\.+$/); 
	if ( m/ /g ) 
	{
		my $oldfile = $_;
		s/ /_/g;
                    if (! -e $oldfile)
                    {
		                 rename $oldfile, $_;
                    }
                    else
                    {
                        print "Could not rename $_ because $oldfile name already exists and can not be overwritten\n";
                    }
             
	}
print "$_\n";
}