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shmdt(2)							     shmdt(2)



NAME

  shmdt	- Detaches a shared memory region

SYNOPSIS

  #include <&lt;sys/shm.h>&gt;

  int shmdt(
	  const	void *addr);

  Application developers may want to specify #include statements for
  <&lt;sys/types.h>&gt;	and  <&lt;sys/ipc.h>&gt; before	the one	for <&lt;sys/shm.h>&gt;	if programs
  are being developed for multiple platforms. The additional #include state-
  ments	are not	required on Tru64 UNIX systems or by ISO or X/Open standards,
  but may be required on other vendors'	systems	that conform to	these stan-
  dards.

STANDARDS

  Interfaces documented	on this	reference page conform to industry standards
  as follows:

  shmdt():  XPG4, XPG4-UNIX

  Refer	to the standards(5) reference page for more information	about indus-
  try standards	and associated tags.

PARAMETERS

  addr	    Specifies the starting virtual address for the shared memory
	    region to be detached.  This is the	address	returned by a previ-
	    ous	shmat()	call.

DESCRIPTION

  The shmdt() function detaches	the shared memory region at the	address
  specified by the addr	parameter.  Other instances of the region attached at
  other	addresses are unaffected.

RETURN VALUES

  Upon successful completion, the shmdt() function decrements the value	of
  shm_nattach in the data structure associated with the	shared memory ID of
  the attached shared memory segment and returns 0 (zero).  Upon failure, the
  shared memory	segment	is not detached, -1 is returned, and errno is set to
  indicate the error.

ERRORS

  The shmdt() function sets errno to the specified values for the following
  conditions:

  [EINVAL]  The	addr parameter does not	specify	the starting address of	a
	    shared memory region.




RELATED	INFORMATION

  Functions: shmat(2), shmctl(2), shmget(2)

  Data structures: shmid_ds(4)

  Standards: standards(5)