In honour of My Mother, God Rest Her Soul.

Thanks Mom!
__outer

/* proth01.c: v2016-02-19 (050) 16:39:54.191 UTC __outer */

#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include <float.h>
#include <math.h>
#include <fenv.h>

static char COPYRIGHT[] = "proth01.c @Copyright 2009-2016 Graven Imagery"; static char VERSIONID[] = "proth01.c: v2016-02-19 (050) 16:39:54.191 UTC"; static char UNIQUEUID[] = "UUID : [722FDA23-D21B-47AF-895D-5AAA58691980]"; static char *Notice;

#define MAX_PRC LDBL_DIG /* 53: 15; 64: 18; */
#define MIN_PRC 9 /* MIN_PRC >= 1e8 */ #define MAX_KEY 1009 /* how madness ends */
#define MAGIC3 769.0L /* it just is, ok? */
#define MOD3 0x0300
#define MAGIC31 7937.0L /* this one is too */
#define MOD31 0x1f00

extern int main(int, char **);
static int crankey331(void), setprc(int), makey(char *);

static long double Mpr, Mpd, PREX, DPEX;
static int PRC, DPM, MNK, MNUM, Mod;

static int crankey331(void) {
long double copy;
int ht256;

fesetround(FE_TOWARDZERO);
do {
copy = Mpd * Mpr;
if( copy >= PREX ) copy /= 10.0L;
Mpd = truncl(copy);

if( Mod == MOD31 ) {
ht256 = (int) fmodl(Mpd, MAGIC31);
if( ht256 == MOD31 ) Mod = MOD3;
else break;
}
else {
ht256 = (int) fmodl(Mpd, MAGIC3);
if( ht256 == MOD3 ) Mod = MOD31;
else break;
}
} while( 1 );
fesetround(FE_TONEAREST);
return( ht256 &0xff );
}

int main( int argc, char **argv ) {
int err, c0, key;

if( (argc < 2) || (argc > 3) ) err = 1;
else if( argc > 2 ) err = setprc( (int) strtol(argv[1], (char **)NULL, 0) );
else err = setprc(MAX_PRC);
if( err == 0 ) err = makey( argv[(argc > 2) ? 2 : 1] );

if( err != 0 ) {
fprintf(stderr, "Usage: %s [prc", argv[0]);
switch( err ) {
case 1 :
default:
fprintf(stderr, " %d-(%d)] key\n", MIN_PRC, MAX_PRC);
break;
case 2 :
fprintf(stderr, ": %d-%d] key - bad precision.\n", MIN_PRC, MAX_PRC);
break;
case 3 :
fprintf(stderr, "] key: %d-%d - key too short.\n", MNK, MAX_KEY);
break;
case 4 :
fprintf(stderr, "] key: %d-%d - invalid key!\n", MNUM, MAX_KEY);
break;
}
(void) exit(err);
}

while( (c0 = getc(stdin)) != EOF ) {
key = crankey331();
c0 = (0x200 - c0 - key) &0xff;
putc(c0, stdout);
}

Mpr = Mpd = 0.0L;
Mod = crankey331();
(void) exit(0);
}

static int setprc( int testprc ) {
if( (testprc > MAX_PRC) || (testprc < MIN_PRC) ) return( 2 );
PREX = powl(10.0L, (long double) testprc);
DPEX = PREX/10.0L;
PRC = testprc;
DPM = testprc - 1;
MNK = (testprc*2) + (testprc*2)/10 + 2; /* minimum alphabetic key length */
MNUM = (testprc*2) + 1; /* minimum literal numeric key */

Notice = COPYRIGHT; while( *Notice++ != 0 ) { Mpr = Mpd = 0.00L; }
Notice = VERSIONID; while( *Notice++ != 0 ) { Mpr = Mpd = MAGIC3; }
Notice = UNIQUEUID; while( *Notice++ != 0 ) { Mpr = Mpd = MAGIC31; }
return( 0 );
}

// #define ZE0 0
// #define EZ1 1

#ifdef ZE0
static char Alpha[27] = "zqxjkvbpygfwmculdrhsnoiate";
#elif EZ1
static char Alpha[27] = "etaionshrdlucmwfgypbvkjxqz";
#else
static char Alpha[27] = "abcdefghijklmnopqrstuvwxyz";
#endif

static int makey( char *keyarg ) {
int j, k, c0, c1, c2;
char *copy, key[MAX_KEY], *search, *enuf;
long double x;

for( c1 = j = 0, copy = key; *keyarg && (j < MAX_KEY); keyarg++ ) {
if( isalnum(*keyarg) ) {
if( isdigit(*keyarg) ) {
*copy++ = *keyarg - '0';
c1++;
}
else *copy++ = tolower(*keyarg);
j++;
}
*keyarg = 0;
}
while( *keyarg ) *keyarg++ = 0;
if( (j < MNK) && (c1 < MNUM) ) return( 3 );

enuf = &key[MNK];
search = Alpha;

for( c0 = c2 = 0; (c1 < j) && (c2 < MNK) && *search; search++ )
for( copy = key, k = 0; k < j; k++, copy++ )
if( *copy == *search ) {
*copy = c0++ %10;
c1++;
if( copy < enuf ) c2++;
}

for( copy = key, k = 0; k < 2; k++ ) {
x = 0.0L;
for( j = 0; (j < PRC) && ((copy - key) < c1); copy++ )
if( *copy || (j && (j < DPM)) ) {
x = (x * 10.0L) + (long double) *copy;
j++;
}
if( x <= DPEX ) return( 4 );
else if( k ) Mpd = truncl(x);
else Mpr = truncl(x) / DPEX;
}

Mod = (*copy &1) ? MOD31 : MOD3;
return( 0 );
}

/* rwo : port from cyph1.c v2013-04-26 (116) 14:40:11.101 UTC */
/* rwo : RTZ v2013-05-16 (136) 00:40:27.792 UTC */
/* rwo : MNK minimizing v2014-02-24 (055) 20:11:21.581 UTC */
/* rwo : Customize key scheduling v2016-02-19 (050) 16:39:54.191 UTC */
/* Monaco Regular 10 *************** proth01.c **************************/

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)