diff options
| -rw-r--r-- | src/hus.c | 21 |
1 files changed, 21 insertions, 0 deletions
@@ -3,6 +3,7 @@ #include <getopt.h> #include <pwd.h> #include <stdlib.h> +#include <stdint.h> #include <string.h> #include <sys/random.h> #include <sys/types.h> @@ -17,6 +18,19 @@ static char *shufrange = NULL; static char **lines = NULL; static size_t nlines = 0; +static size_t random_size_t_r(struct random_data *buf) { + size_t res = 0; + unsigned nbytes = 0; + while (nbytes < sizeof(size_t)) { + int32_t value; + int ret = random_r(buf, &value); + if (ret == -1) { fprintf(stderr, "hus: Kon willekeurigheid niet verlengen\n"); exit(1); } + res |= (size_t)value << (8 * nbytes); + nbytes += 4; + } + return res; +} + static void shuf_lines() { size_t *js = calloc(nlines, sizeof(size_t)); errno = 0; @@ -24,6 +38,13 @@ static void shuf_lines() { for (ssize_t i = nlines - 1; i > 0; i--) { size_t j = js[i] % (nlines-1); + if (j - 1 + (nlines-1) < j) { + struct random_data buf; + int ret = srandom_r(js[i], &buf); + if (ret == -1) { fprintf(stderr, "hus: Kon willekeurigheidsverlenging niet instellen\n"); exit(1); } + do j = random_size_t_r(&buf) % (nlines-1); + while (j - 1 + (nlines-1) < j); + } char *x = lines[i]; lines[i] = lines[j]; |