src/shm-client.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include <unistd.h>
   5 #include <signal.h>
   6 #include <sys/ipc.h>
   7 #include <sys/shm.h>
   8 #include <sys/types.h>
   9 #include <errno.h>
  10
  11 #include "output-plugins/log_ringbuffer.h"
  12
  13 int shm_id;
  14
  15 // -------
  16
  17 void sighandler(int sig)
  18 {
  19     printf("cleaning up\n");
  20     if (shmctl(shm_id, IPC_RMID, NULL) == -1)
  21         perror("shmctl");
  22
  23     exit(0);
  24 }
  25
  26 int init_ringbuffer(struct log_ringbuffer **rb) {
  27     key_t key;
  28     void *buffer;
  29
  30     key = ftok("/etc/prads/prads.conf", 'R');
  31     shm_id = shmget(key, sizeof(struct log_ringbuffer), 0644 | 0);
  32     if (shm_id == -1) {
  33         printf("Could not open ringbuffer. Is prads running?\n");
  34         exit(1);
  35     }
  36
  37     buffer = shmat(shm_id, (void *)0, 0);
  38     if (buffer == (char*)-1) {
  39         perror("shmat");
  40         exit(1);
  41     }
  42
  43     *rb = buffer;
  44
  45     return 0;
  46 }
  47
  48 int main(int argc, char *argv[])
  49 {
  50     int rc;
  51     int tail = 0;
  52     struct log_ringbuffer *ringbuffer;
  53
  54     if ((rc = init_ringbuffer(&ringbuffer)) != 0) {
  55         fprintf(stderr, "Could not initialize ringbuffer\n");
  56         return rc;
  57     }
  58
  59     signal(SIGINT, &sighandler);
  60     signal(SIGTERM, &sighandler);
  61     tail = ringbuffer->head;
  62
  63     for(;;) {
  64         while (tail != ringbuffer->head) {
  65             printf("%s\n", ringbuffer->items[tail].text);
  66
  67             tail = (tail == (RINGBUFFER_ITEMS -1)) ? 0 : tail+1;
  68         }
  69
  70         usleep(50000);
  71     }
  72
  73     return rc;
  74 }
  75