http://qs1969.pair.com?node_id=285093


in reply to Re: Receiving data from many children
in thread Receiving data from many children

Hmm, i tried experimenting with pipes before i posted but couldn't get them to work... Just tried again, copying your example, and *tada*, works! Finally figured out that in my first attempt i had the reader/writer mixed up in the initial pipe... *slaps self*

Future readers, the end result:

my( %pid ); pipe( CHILD, PARENT ); # not PARENT, CHILD! foreach my $num ( "01" .. "25" ) { # if max processes, wait for one to finish if( keys( %pid ) >= 10 ) { &reap() } if( my $pid = fork() ) # parent { $pid{$pid} = $num; } else # child { &child( $num ); exit 0; } } # reap remaining processes while( %pid ) { &reap() } # read child messages close( PARENT ); while( my $child = <CHILD> ) { print "> " . $child; } close( CHILD ); exit 0; sub reap { my( $pid ) = wait(); if( $pid == -1 ) { die( "no more kids to reap!\n" ) } if(! $pid{$pid} ) { die( "why did I see $pid?\n" ) } delete( $pid{$pid} ); } sub child { my( $num ) = $_[0]; close( CHILD ); print "child $num spawned\n"; print PARENT "child $num says hi\n"; }

- ><iper

my JAPH: print"Just another Perl hacker\n"; # ^ look, no space! pretty tricky huh?