1BEGIN { FS = "a" } 2{ 3 n = split ($0, x, FS) 4 if (n != NF) 5 print "botch at ", NR, n, NF 6 for (i=1; i<=n; i++) 7 if ($i != x[i]) 8 print "diff at ", i, x[i], $i 9} 10