sysvipc(7) - Linux manual page (original) (raw)

sysvipc(7) Miscellaneous Information Manual sysvipc(7)

NAME top

   sysvipc - System V interprocess communication mechanisms

DESCRIPTION top

   System V IPC is the name given to three interprocess communication
   mechanisms that are widely available on UNIX systems: message
   queues, semaphore, and shared memory.

Message queues System V message queues allow data to be exchanged in units called messages. Each message can have an associated priority. POSIX message queues provide an alternative API for achieving the same result; see mq_overview(7).

   The System V message queue API consists of the following system
   calls:

   [msgget(2)](../man2/msgget.2.html)
          Create a new message queue or obtain the ID of an existing
          message queue.  This call returns an identifier that is
          used in the remaining APIs.

   [msgsnd(2)](../man2/msgsnd.2.html)
          Add a message to a queue.

   [msgrcv(2)](../man2/msgrcv.2.html)
          Remove a message from a queue.

   [msgctl(2)](../man2/msgctl.2.html)
          Perform various control operations on a queue, including
          deletion.

Semaphore sets System V semaphores allow processes to synchronize their actions. System V semaphores are allocated in groups called sets; each semaphore in a set is a counting semaphore. POSIX semaphores provide an alternative API for achieving the same result; see sem_overview(7).

   The System V semaphore API consists of the following system calls:

   [semget(2)](../man2/semget.2.html)
          Create a new set or obtain the ID of an existing set.  This
          call returns an identifier that is used in the remaining
          APIs.

   [semop(2)](../man2/semop.2.html)
          Perform operations on the semaphores in a set.

   [semctl(2)](../man2/semctl.2.html)
          Perform various control operations on a set, including
          deletion.

Shared memory segments System V shared memory allows processes to share a region a memory (a "segment"). POSIX shared memory is an alternative API for achieving the same result; see shm_overview(7).

   The System V shared memory API consists of the following system
   calls:

   [shmget(2)](../man2/shmget.2.html)
          Create a new segment or obtain the ID of an existing
          segment.  This call returns an identifier that is used in
          the remaining APIs.

   [shmat(2)](../man2/shmat.2.html)
          Attach an existing shared memory object into the calling
          process's address space.

   [shmdt(2)](../man2/shmdt.2.html)
          Detach a segment from the calling process's address space.

   [shmctl(2)](../man2/shmctl.2.html)
          Perform various control operations on a segment, including
          deletion.

IPC namespaces For a discussion of the interaction of System V IPC objects and IPC namespaces, see ipc_namespaces(7).

SEE ALSO top

   [ipcmk(1)](../man1/ipcmk.1.html), [ipcrm(1)](../man1/ipcrm.1.html), [ipcs(1)](../man1/ipcs.1.html), [lsipc(1)](../man1/lsipc.1.html), [ipc(2)](../man2/ipc.2.html), [msgctl(2)](../man2/msgctl.2.html),
   [msgget(2)](../man2/msgget.2.html), [msgrcv(2)](../man2/msgrcv.2.html), [msgsnd(2)](../man2/msgsnd.2.html), [semctl(2)](../man2/semctl.2.html), [semget(2)](../man2/semget.2.html), [semop(2)](../man2/semop.2.html),
   [shmat(2)](../man2/shmat.2.html), [shmctl(2)](../man2/shmctl.2.html), [shmdt(2)](../man2/shmdt.2.html), [shmget(2)](../man2/shmget.2.html), [ftok(3)](../man3/ftok.3.html),
   [ipc_namespaces(7)](../man7/ipc%5Fnamespaces.7.html)

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Linux man-pages 6.10 2024-05-02 sysvipc(7)

Pages that refer to this page:ipcmk(1), ipcrm(1), ipcs(1), lsipc(1), intro(2), ipc(2), msgctl(2), msgget(2), msgop(2), semctl(2), semget(2), semop(2), shmctl(2), shmget(2), shmop(2), ftok(3), proc_sysvipc(5), systemd.exec(5), ipc_namespaces(7)