bash-2.05b$ perl -e'print "$$\n"' 4444236 bash-2.05b$ echo $$ 4100348 bash-2.05b$ perl -e'print "$$\n"' 4431936 bash-2.05b$ echo $$;perl -e'print "$$\n"' 4100348 4268078
typeset -x x=$$ ; perl -e 'print "$ENV{x}\n"'