1 files changed, 69 insertions, 0 deletions
diff --git a/lib/test_shm.c b/lib/test_shm.c
new file mode 100644
index 0000000..7643f7f
--- /dev/null
+++ b/lib/test_shm.c
@@ -0,0 +1,69 @@
+/*
+ * 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: %llx\n", shm_id);
+    sleep(sleep_time);
+    return EXIT_SUCCESS;
+}
+