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// This is a simple program to read from a binary file of random bits and generate
// dice rolls.
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
// Role a single die.
static void rollDie(uint32_t sides, FILE *file) {
uint32_t randVal;
do {
uint32_t numBytes = 0u;
randVal = 0u;
while (1u << (8u*numBytes) <= sides) {
numBytes++;
int c = getc(file);
if (c == EOF) {
printf("Ran out of random data\n");
exit(1);
}
randVal = (randVal << 8u) | getc(file);
}
} while(randVal >= sides);
printf(" %u", randVal + 1u);
}
int main(int argc, char **argv) {
if (argc != 4) {
printf("Usage: dice randFile numDice numSides\n");
return 1;
}
FILE *file = fopen(argv[1], "r");
uint32_t dice = atoi(argv[2]);
uint32_t sides = atoi(argv[3]);
uint32_t i;
printf("Rolling %u %u-sided dice:", dice, sides);
for (i = 0u; i < dice; i++) {
rollDie(sides, file);
}
printf("\n");
fclose(file);
return 0;
}
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