shmunlink(2)                                                    shmunlink(2)



NAME
     shmunlink - deletes a shared memory object

C SYNOPSIS
     #include <sys/mman.h>

     int shmunlink(const char *path);

DESCRIPTION
     path is a pointer to the character string, naming a shared memory object.
     shmunlink deletes the named shared memory object from the file
     namespace. The contents of the shared memory will persist after the call
     to shmunlink, if one or more processes still reference the memory
     object. Once the last reference has been dropped, the space occupied by
     the shared memory object is freed and the object ceases to exist [see
     close(2) and munmap(2)].

     The named shared memory object is unlinked unless one or more of the
     following are true:

     EACCES              Search permission is denied for a component of the
                         path prefix.

     EACCES              Write permission is denied on the directory
                         containing the shared memory object to be removed and
                         the process does not have the super-user privilege.

     EACCES              The parent directory has the sticky bit set and the
                         shared memory object is not writable by the user; the
                         user does not own the parent directory and the user
                         does not own the shared memory object.

     EACCES              Write permission is denied on the shared memory
                         object named by path.

     EFAULT              path points outside the process's allocated address
                         space.

     EINTR               A signal was caught during the shmunlink system
                         call.

     ELOOP               Too many symbolic links were encountered in
                         translating path.

     ENAMETOOLONG        The length of the path argument exceeds {PATHMAX},
                         or the length of a path component exceeds {NAMEMAX}
                         while POSIXNOTRUNC is in effect.

     ENOENT              The named shared memory object does not exist or is a
                         null pathname.





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shmunlink(2)                                                    shmunlink(2)



     ENOTDIR             A component of the path prefix is not a directory.

     EPERM               The named shared memory object is a directory.

     EROFS               The shared memory object to be unlinked is part of a
                         read-only file system.

SEE ALSO
     shmopen(1), close(2), mmap(2), munmap(2)

DIAGNOSTICS
     Upon successful completion, a value of 0 is returned.  Otherwise, a value
     of -1 is returned and errno is set to indicate the error.










































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