'\" te
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.TH sem_unlink 3C "31 Jan 2012" "SunOS 5.11" "Standard C Library Functions"
.SH NAME
sem_unlink \- remove a named semaphore
.SH SYNOPSIS
.LP
.nf
#include <semaphore.h>

\fBint\fR \fBsem_unlink\fR(\fBconst char *\fR\fIname\fR);
.fi

.SH DESCRIPTION
.sp
.LP
The \fBsem_unlink()\fR function removes the semaphore named by the string \fIname\fR. If the semaphore named by \fIname\fR is currently referenced by other processes, then \fBsem_unlink()\fR has no effect on the state of the semaphore.  If one or more processes have the semaphore open when \fBsem_unlink()\fR is called, destruction of the semaphore is postponed until all references to the semaphore have been destroyed by calls to \fBsem_close\fR(3C), \fB_Exit\fR(2), or one of the \fBexec\fR functions (see \fBexec\fR(2)) . Calls to \fBsem_open\fR(3C) to re-create or re-connect to the semaphore refer to a new semaphore after  \fBsem_unlink()\fR is called.  The \fBsem_unlink()\fR call does not block until all references have been destroyed; it returns immediately.
.SH RETURN VALUES
.sp
.LP
Upon successful completion, \fBsem_unlink()\fR returns \fB0\fR. Otherwise, the semaphore is not changed and the function returns a value of \fB\(mi1\fR and sets \fBerrno\fR to indicate the error.
.SH ERRORS
.sp
.LP
The  \fBsem_unlink()\fR function will fail if:
.sp
.ne 2
.mk
.na
\fB\fBEACCES\fR\fR
.ad
.RS 16n
.rt  
Permission is denied to unlink the named semaphore.
.RE

.sp
.ne 2
.mk
.na
\fB\fBENAMETOOLONG\fR\fR
.ad
.RS 16n
.rt  
The length of \fIname\fR string exceeds \fIPATH_MAX\fR, or a pathname component is longer than \fINAME_MAX\fR while \fB_POSIX_NO_TRUNC\fR is in effect.
.RE

.sp
.ne 2
.mk
.na
\fB\fBENOENT\fR\fR
.ad
.RS 16n
.rt  
The named semaphore does not exist.
.RE

.sp
.ne 2
.mk
.na
\fB\fBENOSYS\fR\fR
.ad
.RS 16n
.rt  
The \fBsem_unlink()\fR function is not supported by the system.
.RE

.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(5) for descriptions of the following attributes:
.sp

.sp
.TS
tab() box;
lw(2.75i) |lw(2.75i) 
lw(2.75i) |lw(2.75i) 
.
\fBATTRIBUTE TYPE\fR\fBATTRIBUTE VALUE\fR
_
Interface StabilityCommitted
_
MT-LevelMT-Safe
_
StandardSee \fBstandards\fR(5).
.TE

.SH SEE ALSO
.sp
.LP
\fBexec\fR(2), \fBexit\fR(2), \fBsem_close\fR(3C), \fBsem_open\fR(3C), \fBattributes\fR(5), \fBstandards\fR(5)