SHMGET(2) | System Calls Manual | SHMGET(2) |
shmget
—
#include <sys/shm.h>
int
shmget
(key_t
key, size_t size,
int shmflg);
shmget
() returns the shared memory identifier associated
with the key key.
A shared memory segment is created if either
key is equal to IPC_PRIVATE
,
or key does not have a shared memory segment
identifier associated with it, and the IPC_CREAT
bit
is set in shmflg. If both the
IPC_CREAT
bit and the
IPC_EXCL
bit are set in
shmflg, and key has a shared
memory segment identifier associated with it already, the operation will
fail.
If a new shared memory segment is created, the data structure associated with it (the shmid_ds structure, see shmctl(2)) is initialized as follows:
EACCES
]EEXIST
]IPC_CREAT
and
IPC_EXCL
are set in shmflg,
and a shared memory segment is already associated with
key.EINVAL
]A shared memory segment is to be created,
and size is less than the system imposed minimum,
or greater than the system imposed maximum (refer to the
kern.ipc
values in
sysctl(7)).
ENOENT
]IPC_CREAT
is not set in shmflg and no shared memory segment
associated with key was found.ENOMEM
]ENOSPC
]shmget
system call conforms to
X/Open System Interfaces and Headers Issue 5
(“XSH5”).
October 27, 2008 | NetBSD 9.0 |