Problem Statement

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 software's licensing daemon faithfully records a checkout event when a copy of the software starts and a checkin event when the software finishes to its log file. An example of checkout and checkin events are:

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. Mirror of log file available as a zip here (offsite mirror).

Let's start with the solution:

$$ MODE TUSCRIPT
joblog="mlijobs.txt",jobnrout=0
log=FILE (joblog)
DICT jobnrout CREATE
LOOP l=log
jobout=EXTRACT (l,":License :"|,": :")
 IF (jobout=="out") THEN
  time=EXTRACT (l,":@ :"|,": :"), jobnrout=jobnrout+1
  DICT jobnrout APPEND/QUIET jobnrout,num,cnt,time;" "
 ELSE
  jobnrout=jobnrout-1
 ENDIF
ENDLOOP
DICT jobnrout UNLOAD jobnrout,num,cnt,time
DICT jobnrout SIZE maxlicout
times=SELECT (time,#maxlicout)
PRINT "The max. number of licences out is ", maxlicout
PRINT "at these times: ", times