#!./perl

BEGIN {
    chdir 't' if -d 't';
    @INC = '../lib';
    require './test.pl';
}

BEGIN {
    if ($^O eq 'riscos') {
	skip_all("kill() not implemented on this platform");
    }
}

use strict;

plan tests => 6;

ok( kill(0, $$), 'kill(0, $pid) returns true if $pid exists' );

# It's not easy to come up with an individual PID that is known not to exist,
# so just check that at least some PIDs in a large range are reported not to
# exist.
my $count = 0;
my $total = 30_000;
for my $pid (1 .. $total) {
  ++$count if kill(0, $pid);
}
# It is highly unlikely that all of the above PIDs are genuinely in use,
# so $count should be less than $total.
ok( $count < $total, 'kill(0, $pid) returns false if $pid does not exist' );

# Verify that trying to kill a non-numeric PID is fatal
my @bad_pids = (
    [ undef , 'undef'         ],
    [ ''    , 'empty string'  ],
    [ 'abcd', 'alphabetic'    ],
);

for my $case ( @bad_pids ) {
  my ($pid, $name) = @$case;
  eval { kill 0, $pid };
  like( $@, qr/^Can't kill a non-numeric process ID/, "dies killing $name pid");
}

# Verify that killing a magic variable containing a number doesn't
# trigger the above
{
  my $x = $$ . " ";
  $x =~ /(\d+)/;
  ok(eval { kill 0, $1 }, "can kill a number string in a magic variable");
}