70 lines
2.0 KiB
C
70 lines
2.0 KiB
C
/*
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* test_shm -- program to create a shared memory segment for testing
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*
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* Copyright 2022 Craig Small <csmall@dropbear.xyz>
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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
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* as published by the Free Software Foundation; either version 2
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* of 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 will 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 to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <sys/shm.h>
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#include "c.h"
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#define DEFAULT_SLEEPTIME 300
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#define SHM_SIZE 50
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static void usage(void)
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{
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fprintf(stderr, " %s [options]\n", program_invocation_short_name);
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fprintf(stderr, " -s <seconds>\n");
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exit(EXIT_FAILURE);
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}
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int main(int argc, char *argv[])
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{
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int sleep_time, opt;
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int shm_id;
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void *shm_addr;
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sleep_time = DEFAULT_SLEEPTIME;
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while ((opt = getopt(argc, argv, "s:")) != -1)
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{
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switch(opt)
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{
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case 's':
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sleep_time = atoi(optarg);
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if (sleep_time < 1)
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{
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fprintf(stderr, "sleep time must be 1 second or more\n");
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usage();
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}
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break;
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default:
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usage();
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}
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}
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/* get some shared memory */
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if ( (shm_id = shmget(IPC_PRIVATE, SHM_SIZE, IPC_CREAT | 0666)) < 0)
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xerr(EXIT_FAILURE, "Unable to shmget()");
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if ( (shm_addr = shmat(shm_id, NULL, SHM_RDONLY)) < 0)
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xerr(EXIT_FAILURE, "Unable to shmat()");
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printf("SHMID: %x\n", shm_id);
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sleep(sleep_time);
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return EXIT_SUCCESS;
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}
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