| /* |
| * Copyright (c) 2016 Red Hat Inc. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License as |
| * published by the Free Software Foundation; either version 2 of |
| * the License, or (at your option) any later version. |
| * |
| * This program is distributed in the hope that it would be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| * |
| * 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; |
| } |