Your comment and several others I have seen here suggest that while(FH) and foreach automatically localize $_. But the folowing code seems does not revert to the old $_ after leaving the while loop. What am I missing? Thanks.

use strict; use diagnostics;
$_ = "Before";
print "Before loop= $_\n";
while (<>){
    print "In while loop= $_\n";
    last;
}
print "After while loop= $_\n";

Output:
Before loop= Before
myinput  (entered from the keyboard)
In while loop= myinput

After while loop= myinput
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