93 lines
2.1 KiB
C
93 lines
2.1 KiB
C
/*
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* Copyright (c) 2016 Red Hat Inc.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it would be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*
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* Author: Chunyu Hu <chuhu@redhat.com>
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*
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*/
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#include <stdio.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/time.h>
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static void print_help(void)
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{
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printf("Usage: tst_random <value1> [value2]\n");
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printf(" Generated random will be between value1 and value2.\n");
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printf(" If only value1 is specified, value2 will treated as 0.\n");
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}
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static int get_seed(void)
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{
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struct timeval tv;
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gettimeofday(&tv, NULL);
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return tv.tv_usec;
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}
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static long rand_range(long min, long max)
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{
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return random() % (max - min + 1) + min;
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}
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int main(int argc, char *argv[])
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{
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int opt;
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long min = 0, max = 0;
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long rval = 0;
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char *end;
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while ((opt = getopt(argc, argv, ":h")) != -1) {
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switch (opt) {
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case 'h':
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print_help();
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return 0;
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default:
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print_help();
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return 1;
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}
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}
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if (argc != 2 && argc != 3) {
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print_help();
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return 1;
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}
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max = strtol(argv[1], &end, 10);
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if (argv[1][0] == '\0' || *end != '\0') {
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fprintf(stderr, "ERROR: Invalid range value1 '%s'\n\n",
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argv[optind]);
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print_help();
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return 1;
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}
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if (argc == 3) {
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min = strtol(argv[2], &end, 10);
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if (argv[2][0] == '\0' || *end != '\0') {
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fprintf(stderr, "ERROR: Invalid range value2 '%s'\n\n",
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argv[optind+1]);
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print_help();
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return 1;
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}
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}
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srandom(get_seed());
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rval = (min > max) ? rand_range(max, min) : rand_range(min, max);
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printf("%ld\n", rval);
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return 0;
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}
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