sys.subproj/sem_unlink.2

   1 .\"     $Darwin$
   2 .\"
   3 .\" Wilfredo Sanchez, wsanchez@apple.com
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  24 .Dd June 8, 2000
  25 .Dt SEM_UNLINK 2
  26 .Os Darwin
  27 .Sh NAME
  28 .Nm sem_unlink
  29 .Nd remove a named semaphore
  30 .Sh SYNOPSIS
  31 .Fd #include <semaphore.h>
  32 .Ft int
  33 .Fn sem_unlink "const char *name"
  34 .Sh DESCRIPTION
  35 The named semaphore named
  36 .Fa name
  37 is removed.  If the semaphore is in use my other processes, then
  38 .Fa name
  39 is immeditately dissasociated with the semaphore, but the semaphore
  40 itself will not be removed until all references to it have been
  41 closed.  Subsequent calls to
  42 .Fn sem_open
  43 using
  44 .Fa name
  45 will refer to or create a new semaphore named
  46 .Fa name .
  47 .Pp
  48 If successful,
  49 .Fn sem_close
  50 will return 0.  Otherwise, -1 is returned and
  51 .Va errno
  52 is set, and the state of the semaphore is unchanged.
  53 .Sh ERRORS
  54 .Fn sem_unlink
  55 succeeds unless:
  56 .Bl -tag -width Er
  57 .It Bq Er EACCES
  58 Permission is denied to be remove the semaphore.
  59 .It Bq Er ENAMETOOLONG
  60 .Fa name
  61 exceeded
  62 .Dv SEM_NAME_LEN
  63 characters.
  64 .It Bq Er ENOENT
  65 The named semaphore does not exist.
  66 .El
  67 .Sh SEE ALSO
  68 .Xr semctl 2 ,
  69 .Xr semget 2 ,
  70 .Xr semop 2 ,
  71 .Xr sem_close 2 ,
  72 .Xr sem_open 2
  73 .Sh HISTORY
  74 .Fn sem_unlink
  75 is specified in the POSIX Realtime Extension (1003.1b-1993/1003.1i-1995).