summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--src/hus.c21
1 files changed, 21 insertions, 0 deletions
diff --git a/src/hus.c b/src/hus.c
index 9604954..271fd05 100644
--- a/src/hus.c
+++ b/src/hus.c
@@ -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];