#!/usr/bin/gawk -f

# NOTE: string 1st char at pos. 1.

# Functions.
function process_rec4(rec4, tbl_filter){
   srch_fltr = substr(rec4, 2, 11) # PoD.

   if (srch_fltr in tbl_filter)
   {
      rec4_orig = tbl_filter[srch_fltr]

      if ( (substr(rec4_orig, 591, 10) != substr(rec4, 591, 10)) || (substr(rec4_orig, 752, 2) != substr(rec4, 752, 2)) )
      {
         print rec4_orig >> FILE_OT
         print rec4 >> FILE_OT
         line_cnt_ot += 2
      }
   }
   else
   {
      print "*** ERROR: PoD = " srch_fltr " not in original file!" >> JOB_OUT
      exit 99
   }
}

# Before first line.
BEGIN {
   print ""             >> JOB_OUT
   print "GAwk Started" >> JOB_OUT

   # Constants.
   NUM_RECS_INVC = 4

   # Variables Init.
   line_crnt = ""
   load_fltr = ""
   srch_fltr = ""
   #
   line_cnt_in = 0
   line_cnt_ot = 0
   line_cnt_fltr = 0
   #
   modulo = 69
   #
   rec1 = ""
   rec2 = ""
   rec3 = ""
   rec4 = ""
   rec4_orig = ""
}

# 1st File (filter).
# Load filter to table.
FNR==NR {
   line_cnt_fltr += 1
   line_crnt = $0

   modulo = line_cnt_fltr % NUM_RECS_INVC
   switch (modulo){
      case 0:
         rec4 = line_crnt
         load_fltr = substr(rec4, 2, 11) # PoD.
         tbl_filter[load_fltr] = rec4
         break
      case 1:
         rec1 = line_crnt
         break
      case 2:
         rec2 = line_crnt
         break
      case 3:
         rec3 = line_crnt
         break
      default:
         print "line_cnt_in % NUM_RECS_INVC = " (line_cnt_in % NUM_RECS_INVC) >> JOB_OUT
         exit
         break
   }

   next
}

# For each line of input.
{
   line_cnt_in += 1
   line_crnt = $0

   modulo = line_cnt_in % NUM_RECS_INVC
   switch (modulo){
      case 0:
         rec4 = line_crnt
         process_rec4(rec4, tbl_filter)
         break
      case 1:
         rec1 = line_crnt
         break
      case 2:
         rec2 = line_crnt
         break
      case 3:
         rec3 = line_crnt
         break
      default:
         print "line_cnt_in % NUM_RECS_INVC = " (line_cnt_in % NUM_RECS_INVC) >> JOB_OUT
         exit
         break
   }
}

# After last line.
END {
   print ""           >> JOB_OUT
   print "Read : line_cnt_fltr = @" line_cnt_fltr "@" >> JOB_OUT
   print "Read : line_cnt_in   = @" line_cnt_in "@" >> JOB_OUT
   print "Writ : line_cnt_ot   = @" line_cnt_ot "@" >> JOB_OUT
   print ""           >> JOB_OUT
   print "GAwk Ended" >> JOB_OUT
}