1*23f24377SWarner Losh{ n = length 2*23f24377SWarner Losh d = 0 3*23f24377SWarner Losh for (i = 1; i <= n; i++) 4*23f24377SWarner Losh if ((k = index($0, substr($0, i))) != i) { 5*23f24377SWarner Losh d = 1 6*23f24377SWarner Losh break; 7*23f24377SWarner Losh } 8*23f24377SWarner Losh if (d) 9*23f24377SWarner Losh print $0, "has duplicate letters" 10*23f24377SWarner Losh} 11