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

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