my ($longest_beat, $shortest_beat);

while (<DATA>) { # insert your own filehandle here
  $longest_beat  = $1, next if /longest beat:=\s*(\S+)/; 
  $shortest_beat = $1, next if /shortest beat:=\s*(\S+)/;
}
     
print $longest_beat, "\n";
print $shortest_beat, "\n";

__DATA__
gated window upper limit:=1.15
gated window lower limit:=0.87
gated frame mode:=variable time
gated beats accepted:=631
gated beats rejected:=1
gated longest beat:=1.0455
gated shortest beat:=0.8722
gated average beat:=0.9472
applied zoom:=2.15
zoom origin x:=272
zoom origin y:=288