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/*
* test_shm -- program to create a shared memory segment for testing
*
* Copyright 2022 Craig Small <csmall@dropbear.xyz>
*
* 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 will 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 to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/shm.h>
#include "c.h"
#define DEFAULT_SLEEPTIME 300
#define SHM_SIZE 50
static void usage(void)
{
fprintf(stderr, " %s [options]\n", program_invocation_short_name);
fprintf(stderr, " -s <seconds>\n");
exit(EXIT_FAILURE);
}
int main(int argc, char *argv[])
{
int sleep_time, opt;
int shm_id;
void *shm_addr;
sleep_time = DEFAULT_SLEEPTIME;
while ((opt = getopt(argc, argv, "s:")) != -1)
{
switch(opt)
{
case 's':
sleep_time = atoi(optarg);
if (sleep_time < 1)
{
fprintf(stderr, "sleep time must be 1 second or more\n");
usage();
}
break;
default:
usage();
}
}
/* get some shared memory */
if ( (shm_id = shmget(IPC_PRIVATE, SHM_SIZE, IPC_CREAT | 0666)) < 0)
xerr(EXIT_FAILURE, "Unable to shmget()");
if ( (shm_addr = shmat(shm_id, NULL, SHM_RDONLY)) < 0)
xerr(EXIT_FAILURE, "Unable to shmat()");
printf("SHMID: %x\n", shm_id);
sleep(sleep_time);
return EXIT_SUCCESS;
}
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