SHMGET(2) | System Calls Manual | SHMGET(2) |
shmget
— get
shared memory area identifier
#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 a new shared memory segment is created, the data structure associated with it (the shmid_ds structure, see shmctl(2)) is initialized as follows:
Upon successful completion a positive shared memory segment identifier is returned. Otherwise, -1 is returned and the global variable errno is set to indicate the error.
EACCES
]EEXIST
]IPC_CREAT
and
IPC_EXCL
are set in shmflg,
and a shared memory segment is already associated with
key.EINVAL
]ENOSPC
]ENOENT
]IPC_CREAT
was not set in shmflg and no shared memory segment
associated with key was found.ENOMEM
]November 15, 2014 | OpenBSD-current |