-"tx, hex Hexadecimal, with punctuating dashes.\n"
-"binary Raw binary.\n"
-"base64 Base64-encoded binary; the result is printable ASCII.\n",
+"Generates BITS (by default, 128) random bits. The resulting number is\n"
+"written to FILE, or standard output.\n\n"
+"Randomness is taken from key-timings and environmental noise, although\n"
+"you can disable either (or both) of these sources.\n\n"
+"Options provided are:\n\n"
+"-h, --help Display this help text\n"
+"-b, --bits=BITS\t Generate BITS random bits instead of 128\n"
+"-o, --output=FILE Write bits to FILE, not standard output\n"
+"-f, --format=FORMAT Write bits in FORMAT:\n"
+" tx, hex Hexadecimal\n"
+" binary Raw binary\n"
+" base64 Base64-encoded binary\n"
+"-e, --[no-]env-noise Do [not] read environmental noise\n"
+"-k, --[no-]key-times[=BITS] Do [not] read key timing information\n"
+" (only read BITS bits from key timings)\n",