{
my $tempvar = somefunc();
# do something with $tempvar
}
# $tempvar no longer exists here.

##</code><code>##

{
  local(*INPUT, $/);
  open (INPUT, $file)     || die "can't open $file: $!";
  $var = <INPUT>;
}
# $/ is set back to it's original value here.

##</code><code>##

while (<FH>) {
   next if /^#/;  # Skip comments
   # now do something with $_
}