1SHM_UNLINK(P) POSIX Programmer's Manual SHM_UNLINK(P)
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6 shm_unlink - remove a shared memory object (REALTIME)
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9 #include <sys/mman.h>
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11 int shm_unlink(const char *name);
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15 The shm_unlink() function shall remove the name of the shared memory
16 object named by the string pointed to by name.
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18 If one or more references to the shared memory object exist when the
19 object is unlinked, the name shall be removed before shm_unlink()
20 returns, but the removal of the memory object contents shall be post‐
21 poned until all open and map references to the shared memory object
22 have been removed.
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24 Even if the object continues to exist after the last shm_unlink(), re‐
25 use of the name shall subsequently cause shm_open() to behave as if no
26 shared memory object of this name exists (that is, shm_open() will fail
27 if O_CREAT is not set, or will create a new shared memory object if
28 O_CREAT is set).
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31 Upon successful completion, a value of zero shall be returned. Other‐
32 wise, a value of -1 shall be returned and errno set to indicate the
33 error. If -1 is returned, the named shared memory object shall not be
34 changed by this function call.
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37 The shm_unlink() function shall fail if:
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39 EACCES Permission is denied to unlink the named shared memory object.
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41 ENAMETOOLONG
42 The length of the name argument exceeds {PATH_MAX} or a pathname
43 component is longer than {NAME_MAX}.
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45 ENOENT The named shared memory object does not exist.
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48 The following sections are informative.
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51 None.
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54 Names of memory objects that were allocated with open() are deleted
55 with unlink() in the usual fashion. Names of memory objects that were
56 allocated with shm_open() are deleted with shm_unlink(). Note that the
57 actual memory object is not destroyed until the last close and unmap on
58 it have occurred if it was already in use.
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61 None.
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64 None.
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67 close() , mmap() , munmap() , shmat() , shmctl() , shmdt() , shm_open()
68 , the Base Definitions volume of IEEE Std 1003.1-2001, <sys/mman.h>
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71 Portions of this text are reprinted and reproduced in electronic form
72 from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
73 -- Portable Operating System Interface (POSIX), The Open Group Base
74 Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
75 Electrical and Electronics Engineers, Inc and The Open Group. In the
76 event of any discrepancy between this version and the original IEEE and
77 The Open Group Standard, the original IEEE and The Open Group Standard
78 is the referee document. The original Standard can be obtained online
79 at http://www.opengroup.org/unix/online.html .
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83IEEE/The Open Group 2003 SHM_UNLINK(P)