perl子进程给父进程传数据
pipe(FROM_PARENT, TO_CHILD) or die "pipe: $!";pipe(FROM_CHILD, TO_PARENT) or die "pipe:$!";
select((select(TO_CHILD), $| = 1))); # 自动刷新
select((select(TO_PARENT), $| = 1))); # 自动刷新
if ($pid = fork) {
close FROM_PARENT; close TO_PARENT;
print TO_CHILD "Parent Pid $$ is sending this\n";
chomp($line = );
print "Parent Pid $$ just read this: `$line'\n";
close FROM_CHILD; close TO_CHILD;
waitpid($pid, 0);
} else {
die "cannot fork: $!" unless defined $pid;
close FROM_CHILD; close TO_CHILD;
chomp($line = );
print "Child Pid $$ just read this: `$line'\n";
print TO_PARENT "Child Pid $$ is sending this\n";
close FROM_PARENT; close TO_PARENT;
exit;
}
#!/usr/bin/perl
use strict;
use POSIX ":sys_wait_h";
use Data::Dumper;
my %hash;
print "start\n";
my $count=3;
pipe(READER,WRITER) or die "pipe error $!";
while($count--){
my $pid=fork();
if($pid){
print "In parent\n $$ -- $pid\n";
$hash{$pid}=1;
}else{
close READER;
open(STDOUT,">&WRITER");
#sleep 4;
srand();
my $sltime = 8*rand();
sleep $sltime;
print "In child $$ return value $sltime\n";
exit 0;
}
}
close WRITER;
while(scalar(keys(%hash))>0){
sleep 1;
print Dumper \%hash;
while ((my $collect = waitpid(-1,WNOHANG)) > 0) {
print "$collect exit\n";
delete $hash{$collect};
}
}
while(){
print Dumper $_;
}
# perl test.pl
start
In parent
11359 -- 11360
In parent
11359 -- 11361
In parent
11359 -- 11362
$VAR1 = {
'11360' => 1,
'11362' => 1,
'11361' => 1
};
11361 exit
11362 exit
$VAR1 = {
'11360' => 1
};
$VAR1 = {
'11360' => 1
};
$VAR1 = {
'11360' => 1
};
$VAR1 = {
'11360' => 1
};
$VAR1 = {
'11360' => 1
};
11360 exit
$VAR1 = 'In child 11361 return value 0.727502020665298
';
$VAR1 = 'In child 11362 return value 1.97574310994972
';
$VAR1 = 'In child 11360 return value 6.72100603266884
';
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