#!/usr/local/bin/perl
$countstring = "test";
@chars = split (/\s*/, $countstring);
while ($input = <>) {
$_ = $input;
foreach $char (@chars) {
eval ("\$count = tr/$char/$char/;");
$count{$char} += $count;
}
}
foreach $char (sort (@chars)) {
print ("$char appears $count{$char} times\n");
}