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/* See LICENSE file for copyright and license details. */
#ifdef __linux__
#ifndef _DEFAULT_SOURCE
#define _DEFAULT_SOURCE
#endif
#endif
#ifdef _WIN32
#ifndef _CRT_RAND_S
#define _CRT_RAND_S
#endif
#endif
#include <errno.h>
#include <limits.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifndef _WIN32
#include <unistd.h>
#include <sys/random.h>
#endif
#include "arg.h"
#include "config.h"
char *argv0;
static unsigned char rbuf[256];
static size_t rpos = sizeof rbuf;
static void
die(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
if (fmt[0] && fmt[strlen(fmt)-1] == ':') {
fputc(' ', stderr);
perror(NULL);
} else {
fputc('\n', stderr);
}
exit(1);
}
static void
usage(void)
{
fprintf(stderr, "usage: %s [-v] [-n n] [-l l]\n", argv0 ? argv0 : "rg");
exit(1);
}
static int
fillrand(unsigned char *buf, size_t n)
{
#ifdef _WIN32
size_t i;
unsigned int r;
int k;
for (i = 0; i < n; ) {
if (rand_s(&r) != 0)
return -1;
for (k = 0; k < 4 && i < n; k++)
buf[i++] = (unsigned char)(r >> (8 * k));
}
return 0;
#else
size_t off;
ssize_t r;
off = 0;
while (off < n) {
r = getrandom(buf + off, n - off, 0);
if (r < 0) {
if (errno == EINTR)
continue;
return -1;
}
if (r == 0)
return -1;
off += (size_t)r;
}
return 0;
#endif
}
static unsigned char
randbyte(void)
{
if (rpos >= sizeof rbuf) {
if (fillrand(rbuf, sizeof rbuf) < 0)
die("rg: rng:");
rpos = 0;
}
return rbuf[rpos++];
}
static uint32_t
randu32(void)
{
return ((uint32_t)randbyte() << 24) |
((uint32_t)randbyte() << 16) |
((uint32_t)randbyte() << 8) |
(uint32_t)randbyte();
}
static uint32_t
randbelow(uint32_t n)
{
uint32_t x, min;
if (n <= 1)
return 0;
/* reject [0, 2^32 % n) so x % n is unbiased */
min = (uint32_t)(-n) % n;
do {
x = randu32();
} while (x < min);
return x % n;
}
static int
eint(const char *s)
{
char *end;
long v;
if (s == NULL || s[0] == '\0')
usage();
errno = 0;
v = strtol(s, &end, 10);
if (errno || end == s || *end != '\0' || v < INT_MIN || v > INT_MAX)
die("rg: invalid number '%s'", s);
return (int)v;
}
int
main(int argc, char *argv[])
{
int i, j, n, l, alen;
n = defn;
l = defl;
ARGBEGIN {
case 'n':
n = eint(EARGF(usage()));
break;
case 'l':
l = eint(EARGF(usage()));
break;
case 'v':
puts("rg-" VERSION);
return 0;
default:
usage();
} ARGEND
if (argc)
usage();
if (n < minn || n > maxn)
die("rg: n must be %d..%d", minn, maxn);
if (l < minl || l > maxl)
die("rg: l must be %d..%d", minl, maxl);
alen = (int)strlen(alphabet);
if (alen < 1)
die("rg: empty alphabet");
for (i = 0; i < n; i++) {
for (j = 0; j < l; j++)
putchar(alphabet[randbelow((uint32_t)alen)]);
putchar('\n');
}
return 0;
}
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