- fprintf(out, "Without DIR2, lists duplicated files in DIR1. With DIR2, list files common to both directories. With DIR2 starting with a ^, list files found in DIR1 which do not exist in DIR2.\n");
+ fprintf(out, "Without DIR2, lists duplicate files found in DIR1. With DIR2, lists files common to both directories. With the not: prefix, lists files found in DIR1 which do not exist in DIR2.\n");