It works now. Thanks all. 
$ perl -Mstrict -MPOSIX -wE 'my $pid = fork; if( $pid ){ kill TERM => 
+$pid; foreach( 1..5 ){ sleep 1; waitpid $pid => WNOHANG; my $rv = kil
+l 0 => $pid; say $rv; exit unless $rv; } kill KILL => $pid; waitpid $
+pid => 0;  } else { BEGIN{ $SIG{TERM}=sub{ say "TERM!"; }; } sleep 3;
+  exit; }'
TERM!
1
1
0
$ perl -Mstrict -MPOSIX -wE 'my $pid = fork; if( $pid ){ kill TERM => 
+$pid; foreach( 1..3 ){ sleep 1; waitpid $pid => WNOHANG; my $rv = kil
+l 0 => $pid; say $rv; exit unless $rv; } kill KILL => $pid; waitpid $
+pid => 0;  } else { BEGIN{ $SIG{TERM}=sub{ say "TERM!"; }; } sleep 5;
+  exit; }'
TERM!
1
1
1
$

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In reply to WNOHANG seem to help by petr999
in thread Check if forked process is dead by petr999

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