ref: a3b68e649d2da36d19d78106134d1114f06b56e1 dir: /testdir/t.split9a/
BEGIN { FS = "a" } { n = split ($0, x, FS) if (n != NF) print "botch at ", NR, n, NF for (i=1; i<=n; i++) if ($i != x[i]) print "diff at ", i, x[i], $i }