Shell Programming and Scripting

cat input.txt | awk 'BEGIN{ 
  while (getline  > 0 && NF > 0){
      data_array[$1]+=0
      if ( NR > 1 ){
        C1 = $1 
        C2 = $2

        if ( P1 == C1 && P2 != C2){
            if ( (P2+1)%16 != C2 ){
              data_array[$1]++
            }
        }
      }
      P1 = $1
      P2 = $2
  }
}

END{
  for (var in data_array)
    if ( data_array[var] == 1)
      print "Channel " var " : "  data_array[var] " discontinuity"
    else
      print "Channel " var " : "  data_array[var] " discontinuities"
}'

$ cat d2
400 0
400 1 xx
400 1 xxxx
400 2
400 3
400 0 //
400 0 ////
400 1
400 2
400 3 xx
400 3 xxxx
400 0
400 1 //
400 1 ////

$ cat test.sh
#!/bin/sh

awk  '
   ch!=$1{ch=$1;seq=$2}  #initialize with new channel
   ch==$1{   #channel same as stored
             if(seq==$2) next;  #if same, skip to next line
             else if((++seq%16)!=$2) { #increment and cycle the counter; compare
                 cntr[$1]++
                 seq=$2     #reset seq
                 print "Disc. " $0 " seq: " seq   #debug; uncomment to check what was grabbed
             }
   }END{
     for(i in cntr) {
       print "Channel " i " has " cntr[i] " discontinuities" 
   }
 }' < $1

$ ./test.sh d2 
Disc. 400 0 // seq: 0
Disc. 400 0 seq: 0
Channel 400 has 2 discontinuities

my $pre;
while(<DATA>){
	my @tmp = split;
	push @{$hash{$tmp[0]}}, $tmp[1];
}
foreach my $key(keys %hash){
	my $cnt;
	my @arr = @{$hash{$key}};
	for(my $i=1;$i<=$#arr;$i++){
		#$cnt ++ if $arr[$i-1]<$arr[$i] && $arr[$i]>($arr[$i+1]||-10000);
		$cnt++ if not (($arr[$i-1]==$arr[$i]-1) || $arr[$i]==$arr[$i+1]-1);
	}
	print $key," has ", $cnt, " incontinuity\n" if $cnt;
}
__DATA__
160 13
160 14
160 15
160 0
160 1
160 4
160 2
409 2
409 3
409 5