summaryrefslogtreecommitdiff
path: root/test-genrandom.c
blob: 8cefe6cfed87c8fe0c11d1263dae01639d2bd0f0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
/*
 * Simple random data generator used to create reproducible test files.
 * This is inspired from POSIX.1-2001 implementation example for rand().
 * Copyright (C) 2007 by Nicolas Pitre, licensed under the GPL version 2.
 */
 
#include <stdio.h>
#include <stdlib.h>
 
int main(int argc, char *argv[])
{
	unsigned long count, next = 0;
	unsigned char *c;
 
	if (argc < 2 || argc > 3) {
		fprintf( stderr, "Usage: %s <seed_string> [<size>]", argv[0]);
		return 1;
	}
 
	c = (unsigned char *) argv[1];
	do {
		next = next * 11 + *c;
	} while (*c++);
 
	count = (argc == 3) ? strtoul(argv[2], NULL, 0) : -1L;
 
	while (count--) {
		next = next * 1103515245 + 12345;
		if (putchar((next >> 16) & 0xff) == EOF)
			return -1;
	}
 
	return 0;
}