The select() function will tell you when there is data waiting to be read on a socket. If the connection is lost, select() will lie and say there is something to be read. When you try to read the line, sysread will return undef. 
   my $bit_in = '';
   my $r_bit;
   vec($bit_in, fileno($f), 1) = 1;
   while(1) {
      select($r_bit = $bit_in, undef, undef, tick_len);

# if select said there was data...
      if(vec($r_bit,fileno($f),1)) {
         my $in;

# connection lost if sysread returns undef
         return unless $f->sysread($in, 1);

# otherwise, it's good data
         $str .= $in;
         last if $in eq "\n";
      }
   }

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In reply to Re: How do i detect that the client has disconnected ? (i'm using sysread/write) by entropy
in thread How do i detect that the client has disconnected ? (i'm using sysread/write) by shlomi

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