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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (c) 2016 Red Hat Inc.
* Author: Chunyu Hu <chuhu@redhat.com>
*/
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
static void print_help(void)
{
printf("Usage: tst_random <value1> [value2]\n");
printf(" Generated random will be between value1 and value2.\n");
printf(" If only value1 is specified, value2 will treated as 0.\n");
}
static int get_seed(void)
{
struct timeval tv;
gettimeofday(&tv, NULL);
return tv.tv_usec;
}
static long rand_range(long min, long max)
{
return random() % (max - min + 1) + min;
}
int main(int argc, char *argv[])
{
int opt;
long min = 0, max = 0;
long rval = 0;
char *end;
while ((opt = getopt(argc, argv, ":h")) != -1) {
switch (opt) {
case 'h':
print_help();
return 0;
default:
print_help();
return 1;
}
}
if (argc != 2 && argc != 3) {
print_help();
return 1;
}
max = strtol(argv[1], &end, 10);
if (argv[1][0] == '\0' || *end != '\0') {
fprintf(stderr, "ERROR: Invalid range value1 '%s'\n\n",
argv[optind]);
print_help();
return 1;
}
if (argc == 3) {
min = strtol(argv[2], &end, 10);
if (argv[2][0] == '\0' || *end != '\0') {
fprintf(stderr, "ERROR: Invalid range value2 '%s'\n\n",
argv[optind+1]);
print_help();
return 1;
}
}
srandom(get_seed());
rval = (min > max) ? rand_range(max, min) : rand_range(min, max);
printf("%ld\n", rval);
return 0;
}
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