sys/shm_unlink.2

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  23 .Dd September 20, 1999
  24 .Dt SHM_UNLINK 2
  25 .Os Darwin
  26 .Sh NAME
  27 .Nm shm_unlink
  28 .Nd remove shared memory object
  29 .Sh SYNOPSIS
  30 .Fd #include <sys/mman.h>
  31 .Ft int
  32 .Fn shm_unlink "const char *name"
  33 .Sh DESCRIPTION
  34 The
  35 .Fn shm_unlink
  36 function removes the shared memory object named by
  37 .Fa name .
  38 If no process has the file open, then all resources associated
  39 with the object are reclaimed.
  40 If one or more process have the object open, the name removed,
  41 but the removal of the memory object is delayed until all
  42 references to it have been closed.
  43 .Sh RETURN VALUES
  44 Upon successful completion, a value of 0 is returned.
  45 Otherwise, a value of -1 is returned and
  46 .Va errno
  47 is set to indicate the error, and the named shared memory object
  48 will remain unchanged.
  49 .Sh ERRORS
  50 The
  51 .Fn shm_unlink
  52 succeeds unless:
  53 .Bl -tag -width Er
  54 .It Bq Er EACCES
  55 Permission is denied to be remove the object.
  56 .It Bq Er ENAMETOOLONG
  57 .Fa name
  58 exceeded
  59 .Dv SHM_NAME_MAX
  60 characters.
  61 .It Bq Er ENOENT
  62 The named object does not exist.
  63 .El
  64 .Sh SEE ALSO
  65 .Xr close 2 ,
  66 .Xr mmap 2 ,
  67 .Xr munmap 2 ,
  68 .Xr shmat 2 ,
  69 .Xr shmctl 2 ,
  70 .Xr shm_open 2
  71 .Sh HISTORY
  72 .Fn shm_open
  73 is specified in the POSIX Realtime Extension (1003.1b-1993/1003.1i-1995).