title: How to tie a network connection to a PID without using lsof or netstat?
body: <p>Is there a way to tie a network connection to a PID (process ID) without forking to lsof or netstat?</p>
  
  <p>Currently lsof is being used to poll what connections belong which process ID.  However lsof or netstat can be quite expensive on a busy host and would like to avoid having to fork to these tools.</p>
  
  <p>Is there someplace similar to /proc/$pid where one can look to find this information?  I know what the network connections are by examining /proc/net but can't figure out how to tie this back to a pid.  Over in /proc/$pid, there doesn't seem to be any network information.</p>
  
  <p>The target hosts are Linux 2.4 and Solaris 8 to 10.  If possible, a solution in Perl, but am willing to do C/C++.</p>
  
  <p><strong>additional notes:</strong></p>
  
  <p>I would like to emphasize the goal here is to tie a network connection to a PID.  Getting one or the other is trivial, but putting the two together in a low cost manner appears to be difficult.  Thanks for the answers to so far!</p>