Re^3: Getting a return code from waitpid in Windows

[ikegami]

You call waitpid after you've reaped the process, causing causing an error ($? = -1;, error message in $!).

You gotta check $? after the successful call to waitpid.

use POSIX qw( WNOHANG );

my $pid = system(1,'perl -e"sleep(4); exit(5);"');

while (1) {
   my $wait = waitpid($pid, WNOHANG);
   die $! if $wait < 0;
   last if $wait > 0;
}

print "Command completed with exit code $?.\n";

I presume you actually do something else in the loop? If not, there's no reason to use WHOHANG.

my $pid = system(1,'perl -e"sleep(4); exit(5);"');

waitpid($pid, 0);
die $! if $? < 0;
print "Command completed with exit code $?.\n";