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.\" Copyright (C) 2000 Jason Evans <jasone@FreeBSD.org>.
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.\" $FreeBSD: src/lib/libc_r/man/sem_open.3,v 1.7 2001/10/01 16:09:09 ru Exp $
.Dd $Mdocdate: May 31 2007 $
.Dt SEM_OPEN 3
.Os
.Sh NAME
.Nm sem_open ,
.Nm sem_close ,
.Nm sem_unlink
.Nd named semaphore operations
.Sh SYNOPSIS
.Fd #include <semaphore.h>
.Ft sem_t *
.Fn sem_open "const char *name" "int oflag" "..."
.Ft int
.Fn sem_close "sem_t *sem"
.Ft int
.Fn sem_unlink "const char *name"
.Sh DESCRIPTION
The
.Fn sem_open ,
.Fn sem_close ,
and
.Fn sem_unlink
functions are not supported by this implementation.
.Sh RETURN VALUES
.Fn sem_open
returns SEM_FAILED and sets
.Va errno
to indicate an error.
.Fn sem_close
and
.Fn sem_unlink
return -1 and set
.Va errno
to indicate an error.
.Sh ERRORS
.Fn sem_open ,
.Fn sem_close ,
and
.Fn sem_unlink
will fail:
.Bl -tag -width Er
.It Bq Er ENOSYS
Function not supported by this implementation.
.El
.Sh SEE ALSO
.Xr sem_destroy 3 ,
.Xr sem_getvalue 3 ,
.Xr sem_init 3 ,
.Xr sem_post 3 ,
.Xr sem_wait 3
.Sh STANDARDS
.Fn sem_open ,
.Fn sem_close ,
and
.Fn sem_unlink
conform to
.St -p1003.1-96 .