This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface

       Names of memory objects that were allocated with open() are deleted with unlink() in the  usual  fashion.
       Names of memory objects that were allocated with shm_open() are deleted with shm_unlink().  Note that the
       actual  memory  object  is  not  destroyed  until  the last close and unmap on it have occurred if it was
       already in use.

       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 http://www.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page are most likely to have  been  introduced
       during   the   conversion  of  the  source  files  to  man  page  format.  To  report  such  errors,  see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                                   2017                                    SHM_UNLINK(3POSIX)

       The  shm_unlink()  function shall remove the name of the shared memory object named by the string pointed
       to by name.

       If one or more references to the shared memory object exist when the object is unlinked, the  name  shall
       be  removed before shm_unlink() returns, but the removal of the memory object contents shall be postponed
       until all open and map references to the shared memory object have been removed.

       Even if the object continues to exist after the last shm_unlink(), reuse of the name  shall  subsequently
       cause  shm_open()  to  behave as if no shared memory object of this name exists (that is, shm_open() will
       fail if O_CREAT is not set, or will create a new shared memory object if O_CREAT is set).

       The shm_unlink() function shall fail if:

       EACCES Permission is denied to unlink the named shared memory object.

       ENOENT The named shared memory object does not exist.

       The shm_unlink() function may fail if:

       ENAMETOOLONG
              The  length  of the name argument exceeds {_POSIX_PATH_MAX} on systems that do not support the XSI
              option or exceeds {_XOPEN_PATH_MAX} on XSI systems, or has a pathname  component  that  is  longer
              than   {_POSIX_NAME_MAX}   on  systems  that  do  not  support  the  XSI  option  or  longer  than
              {_XOPEN_NAME_MAX} on XSI systems.  A call to shm_unlink() with a name argument that  contains  the
              same  shared  memory  object name as was previously used in a successful shm_open() call shall not
              give an [ENAMETOOLONG] error.

       Thefollowingsectionsareinformative.

       None.

       A future version might require the shm_open() and shm_unlink() functions to  have  semantics  similar  to
       normal file system operations.

       shm_unlink — remove a shared memory object (REALTIME)

       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.

       None.

       Upon successful completion, a value of zero shall be  returned.   Otherwise,  a  value  of  -1  shall  be
       returned and errno set to indicate the error. If -1 is returned, the named shared memory object shall not
       be changed by this function call.

close(), mmap(), munmap(), shmat(), shmctl(), shmdt(), shm_open()

       The Base Definitions volume of POSIX.1‐2017, <sys_mman.h>

       #include <sys/mman.h>

       int shm_unlink(const char *name);