The Single UNIX ® Specification, Version 2
Copyright © 1997 The Open Group


shmdt - shared memory detach operation


#include <sys/shm.h>

int shmdt(const void *shmaddr);


The shmdt() function detaches the shared memory segment located at the address specified by shmaddr. from the address space of the calling process.


Upon successful completion, shmdt() will decrement the value of shm_nattch in the data structure associated with the shared memory ID of the attached shared memory segment and return 0.

Otherwise, the shared memory segment will not be detached, shmdt() will return -1 and errno will be set to indicate the error.


The shmdt() function will fail if:
The value of shmaddr is not the data segment start address of a shared memory segment.




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 described in IPC can be easily modified to use the alternative interfaces.




exec, exit(), fork(), shmat(), shmctl(), shmget(), shm_open(), shm_unlink(), <sys/shm.h>, IPC.


Derived from Issue 2 of the SVID.

UNIX ® is a registered Trademark of The Open Group.
Copyright © 1997 The Open Group
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