#! /usr/bin/perl
use strict;
use warnings;
use IO::Socket::INET6;
use Time::HiRes qw(sleep);
@ARGV==5 or die "$0 <hostname> <port> <string> <timeout> <tries>";
my($hostname,$port,$string,$timeout,$tries)=@ARGV;
for our $try (1..$tries) {
  sub ts() {
    return localtime()." PID=$$ #$try: ";
  }
  warn ts()."connect($hostname,$port)...\n";
  my $sock=IO::Socket::INET6->new(
      "Proto"   =>"tcp",
      "PeerAddr"=>$hostname,
      "PeerPort"=>$port,
  );
  if (!$sock) {
    warn ts()."connect($hostname,$port)=$!";
    sleep $timeout;
    next;
  }
  warn ts()."connect($hostname,$port): done.\n";
  my $buf="";
  my $remains=$timeout;
  while ($remains>0) {
    my $rin="";
    vec($rin,fileno($sock),1)=1;
    my($nfound,$timeleft)=select($rin,"",$rin,$remains);
    die "select nfound=$nfound: $!" if $nfound<0;
    die "select timeleft=$timeleft" if $timeleft<0;
    $remains=$timeleft;
    if (!$nfound) {
      $remains==0 or die "remains=$remains";
      last;
    }
    my $c;
    my $got=sysread $sock,$c,1;
    my $fail;
    if (!defined $got) {
      warn ts()."sysread: $!";
      $fail=1;
    }
    if ($got==0) {
      warn ts()."sysread: EOF";
      $fail=1;
    }
    if (!$fail) {
      $got==1 or die "sysread=$got!=1";
      length($c)==1 or die "sysread->c=".length($c)."!=1";
      $buf.=$c;
    }
    last if length($buf)>=length($string);
#    warn ts()."remains=<$remains> buf=<$buf>\n";
    last if $fail;
  }
  close $sock or warn ts()."close: $!";
  if ($buf eq $string) {
    warn ts()."PASS\n";
    print "PASS\n";
    exit 0;
  }
  warn ts()."buf=<$buf>, sleep $remains";
  sleep $remains or warn ts()."sleep=$!";
}
warn ts()."FAIL\n";
print "FAIL\n";