Text processing/Max licenses in use

Text processing/Max licenses in use
You are encouraged to solve this task according to the task description, using any language you may know.

A company currently pays a fixed sum for the use of a particular licensed software package. In determining if it has a good deal it decides to calculate its maximum use of the software from its license management log file.

Assume the softwares file faithfully records a checkout event when a copy of the software starts and a checkin event when the software finishes. An example of checkout and checkin events are:

 License OUT @ 2008/10/03_23:51:05 for job 4974
 ...
 License IN  @ 2008/10/04_00:18:22 for job 4974

Save the 10,000 line log file from here* into a local file then write a program to scan the file extracting both the maximum licenses that were out at any time, and the time(s) at which this occurs.

• Note: The page uses javascript to display a text file, so it may be best to cut-n-paste from a browser to a text file rather than downloading the URL.

Python

Python 2.6 <python>import urllib

def max_out(logfile):

   maxout =0
   maxouttimes = []
   out = 0
   for line in logfile:
       direction = line[8]
       time = line[14:33]
       if direction == 'O':
           out +=1
           if out > maxout:
               maxout = out
               maxouttimes = [time]
           elif out == maxout:
               maxouttimes.append(time)
       else:
           out -=1
   return maxout, maxouttimes

if __name__ == '__main__':

   log = file('license_example_log.txt')
   maxout, maxouttimes = max_out(log)
   log.close()
   print "Maximum simultaneous license use is %i at the following times:\n %s" % (
       maxout, '\n '.join(maxouttimes))</python>

Example output:

Maximum simultaneous license use is 99 at the following times:
 2008/10/03_08:39:34
 2008/10/03_08:40:40