Sorry, but you are mistaken. 
$ perl -E'
   say "".localtime;
   open my $fh, q{perl -e sleep |};
   say "".localtime;
'
Sun Feb 20 13:25:05 2011
Sun Feb 20 13:25:05 2011
[hung waiting for child to exit]

[download]

or how about 

$ perl -E'
   open my $fh, q{perl -E'\''sleep 1; say STDERR "C"'\'' |};
   say "P";
'
P
C

[download]

In reply to Re^5: how to kill background process when script exit? by ikegami
in thread how to kill background process when script exit? by Allasso

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