Unless you really want to print every time you find a rougue char you can just use tr:

$str = join '', map{chr}0..255;
$str =~ tr/\11\12\40-\176//cd;       # ascify aka remove all crap char
+s
print $str, $/;
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The /c is complement the list of desired characters, the /d deletes those that don't match. The good printable ASCII characters are specified in octol but you can use hex. To do what you are doing with a regex (here the chars are expressed as hex just to shown TIMTOWTDI):

while (<DATA>) {
    while ( m/([^\x09\x0A\x20-\x7E])/g ) {
        printf "Found chr %d on line %d at pos %d\n", ord($1), $., pos
+($_);
    }
}
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