#!/usr/bin/python -u

"""
Waits for Nmap to start and records the number of file descriptors it has open
to the file specified as its command-line argument. Once Nmap dies, the program
terminates.
"""

import time
import os
import subprocess
import sys

with open(sys.argv[1], "w") as f:

  while True:
      p = subprocess.Popen("pgrep nmap", shell=True, stdout=subprocess.PIPE)
      pid_out = p.communicate()[0]
      if not pid_out:
          continue
      else:
          pid = pid_out.rstrip("\n")
          break

  try:
    while True:
      f.write("%s\n" % (len(os.listdir('/proc/%s/fd' % pid))))
      f.flush()
      time.sleep(0.1)
  except OSError:
    pass