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OpenSolaris 2009.06 - man page for semids (opensolaris section 2)

semids(2)							   System Calls 							 semids(2)

NAME
semids - discover all semaphore identifiers
SYNOPSIS
#include <sys/sem.h> int semids(int *buf, uint_t nids, uint_t *pnids);
DESCRIPTION
The semids() function copies all active semaphore 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 semaphore 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 semaphore 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 semaphore identifiers in the system, buf is ignored.
RETURN VALUES
Upon successful completion, semids() returns 0. Otherwise, -1 is returned and errno is set to indicate the error.
ERRORS
The semids() function will fail if: EFAULT The buf or pnids argument points to an illegal address.
USAGE
The semids() function returns a snapshot of all the active semaphore identifiers in the system. More may be added and some may be removed before they can be used by the caller.
EXAMPLES
Example 1 semids() example This is sample C code indicating how to use the semids() function. void examine_semids() { int *ids = NULL; uint_t nids = 0; uint_t n; int i; for (;;) { if (semids(ids, nids, &n) != 0) { perror("semids"); 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_semid(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), semctl(2), semget(2), semop(2), attributes(5) SunOS 5.11 8 Mar 2000 semids(2)