Shell Programming and Scripting

BEGIN {
  FS=OFS="|"

  FLD_max=12
}
# NF - number of fields in the current record
# if the number of fields in mthe current record is less than maximum number 
# of fields - execute the action: if "rec" is NOT empty - concatenate it with
# the current record [rec OFS $0$0]; if "rec" IS empty - assign the current
# record/line to it [$0]. Increment the "running" number of fields [fld] by the
# number of the fields in the current record [NF]. Proceed to the next record
# [next].
NF < FLD_max {rec=(rec != "") ? rec OFS $0 : $0; fld+=NF;next }

# if the running number of fields [fld] is greater tan the MAX: output the
# "rec" and initialize "rec" to be empty and the running number of fields to be "0"

fld >= FLD_max { print rec; rec=""; fld=0 }

# if NONE of the above actions could be executed - "print" the current 
# record/line: "1" is a shortname for "print $0"
1

BEGIN {
  FS=OFS="|"

  FLD_max=12

  stderr="cat 2>&1"
}
NF < FLD_max {printf("Bad record: [%d] :: [%s]\n", FNR, $0) | stderr; rec=(rec != "") ? rec OFS $0 : $0; fld+=NF;next }
fld >= FLD_max { print rec; rec=""; fld=0 }
1