weidagang2046的專欄

???? sub ?ping_a_host?{
?????? my ? $host ? = ? shift ;
??????`ping? - i? 1 ? - c? 1 ? $host ? 2 >/ dev / null`? =~ ? / 0 ?packets?rec / ? ? ? 0 ? : ? 1 ;
????}

???? my ? %pid_to_host ;
???? my ? %host_result ;

???? sub ?wait_for_a_kid?{
?????? my ? $pid ? = ? wait ;
?????? return ? 0 ? if ? $pid ? < ? 0 ;
?????? my ? $host ? = ? delete ? $pid_to_host { $pid }
????????or? warn ( " Why?did?I?see?$pid?($?)\n " ) , ? next ;
?????? warn ? " reaping?$pid?for?$host\n " ;
?????? $host_result { $host }? = ?$ ? ? ? ? 0 ? : ? 1 ;
?????? 1 ;
????}

???? my ? @hosts ? = ? map ? " 10.0.1.$_ " , ? " 001 " .. " 254 " ;

???? for ?( @hosts )?{
??????wait_for_a_kid()? if ? keys ? %pid_to_host ? > ? 10 ;
?????? if ?( my ? $pid ? = ? fork )?{
???????? # #?parent?does
???????? $pid_to_host { $pid }? = ? $_ ;
???????? warn ? " $pid?is?processing?$_\n " ;
??????}? else ?{? # ?child?does
????????##?child?does
???????? exit ? ! ping_a_host( $_ );
??????}
????}

???? # #?final?reap:
???? 1 ? while ?wait_for_a_kid();

???? for ?( sort ? keys ? %host_result )?{
?????? print ? " $_?is? " , ?( $host_result { $_ }? ? ? " good " ? : ? " bad " ) , ? " \n " ;
????}