Section: POSIX Programmer's Manual (3P)
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
--- XSI shared memory detach operation
int shmdt(const void *shmaddr);
function operates on XSI shared memory (see the Base Definitions volume of POSIX.1-2017,
, Shared Memory Object).
It is unspecified whether this function interoperates with the
realtime interprocess communication facilities defined in
function detaches the shared memory segment located at the address
from the address space of the calling process.
Upon successful completion,
shall decrement the value of
in the data structure associated with the shared memory ID of the
attached shared memory segment and return 0. Also, the
timestamp shall be set to the current time, as described in
, IPC General Description.
Otherwise, the shared memory segment shall not be detached,
shall return -1, and
shall be set to indicate the error.
function shall fail if:
The value of
is not the data segment start address of a shared memory segment.
The following sections are informative.
The POSIX Realtime Extension defines alternative interfaces for interprocess
communication. Application developers who need to use IPC should
design their applications so that modules using the IPC routines
, XSI Interprocess Communication
can be easily modified to use the alternative interfaces.
, XSI Interprocess Communication,
The Base Definitions volume of POSIX.1-2017,
Section 3.346, Shared Memory Object,
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
In the event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
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