shmids(2)							   System Calls 							 shmids(2)

NAME

       shmids - discover all shared memory identifiers

SYNOPSIS

       #include <sys/shm.h>

       int shmids(int *buf, uint_t nids, uint_t *pnids);

DESCRIPTION

       The  shmids()  function copies all active shared memory identifiers from the system into the user-defined buffer specified by buf, provided
       that the number of such identifiers is not greater than the number of integers the buffer can contain, as specified by nids.  If  the  size
       of the buffer is insufficient to contain all of the active shared memory identifiers in the system, none are copied.

       Whether or not the size of the buffer is sufficient to contain all of them, the number of active shared memory identifiers in the system is
       copied into the unsigned integer pointed to by pnids.

       If nids is 0 or less than the number of active shared memory identifiers in the system, buf is ignored.

RETURN VALUES

       Upon successful completion, shmids() returns 0.	Otherwise, -1 is returned and errno is set to indicate the error.

ERRORS

       The shmids() function will fail if:

       EFAULT	       The buf or pnids argument points to an illegal address.

USAGE

       The shmids() function returns a snapshot of all the active shared memory identifiers in the system.  More may be  added	and  some  may	be
       removed before they can be used by the caller.

EXAMPLES

       Example 1: shmids() example

       This is sample C code indicating how to use the shmids() function.

       void
       examine_shmids()
       {
	    int *ids = NULL;
	    uint_t nids = 0;
	    uint_t n;
	    int i;

	    for (;;) {
		 if (shmids(ids, nids, &n) != 0) {
		      perror("shmids");
		      exit(1);
		 }
		 if (n <= nids)     /* we got them all */
		      break;
		 /* we need a bigger buffer */
		 ids = realloc(ids, (nids = n) * sizeof (int));
	    }

	    for (i = 0; i < n; i++)
		 process_shmid(ids[i]);

	    free(ids);
       }

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |Async-Signal-Safe 	   |
       +-----------------------------+-----------------------------+

SEE ALSO

       ipcrm(1), ipcs(1), intro(2), shmctl(2), shmget(2), shmop(2), attributes(5)

SunOS 5.10							    8 Mar 2000								 shmids(2)