mirror of https://github.com/mkerrisk/man-pages
80 lines
2.7 KiB
Plaintext
80 lines
2.7 KiB
Plaintext
.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
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.TH "SEM_UNLINK" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
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.\" sem_unlink
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.SH NAME
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sem_unlink \- remove a named semaphore (\fBREALTIME\fP)
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.SH SYNOPSIS
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.LP
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\fB#include <semaphore.h>
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.br
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.sp
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int sem_unlink(const char *\fP\fIname\fP\fB); \fP
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\fB
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.br
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\fP
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.SH DESCRIPTION
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.LP
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The \fIsem_unlink\fP() function shall remove the semaphore named by
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the string \fIname\fP. If the semaphore named by
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\fIname\fP is currently referenced by other processes, then \fIsem_unlink\fP()
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shall have no effect on the state of the
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semaphore. If one or more processes have the semaphore open when \fIsem_unlink\fP()
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is called, destruction of the semaphore is
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postponed until all references to the semaphore have been destroyed
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by calls to \fIsem_close\fP(), \fI_exit\fP(), or \fIexec\fP. Calls
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to \fIsem_open\fP() to recreate or reconnect
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to the semaphore refer to a new semaphore after \fIsem_unlink\fP()
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is called. The \fIsem_unlink\fP() call shall not block until
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all references have been destroyed; it shall return immediately.
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.SH RETURN VALUE
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.LP
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Upon successful completion, the \fIsem_unlink\fP() function shall
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return a value of 0. Otherwise, the semaphore shall not be
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changed and the function shall return a value of -1 and set \fIerrno\fP
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to indicate the error.
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.SH ERRORS
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.LP
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The \fIsem_unlink\fP() function shall fail if:
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.TP 7
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.B EACCES
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Permission is denied to unlink the named semaphore.
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.TP 7
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.B ENAMETOOLONG
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The length of the \fIname\fP argument exceeds {PATH_MAX} or a pathname
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component is longer than {NAME_MAX}.
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.TP 7
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.B ENOENT
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The named semaphore does not exist.
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.sp
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.LP
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\fIThe following sections are informative.\fP
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.SH EXAMPLES
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.LP
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None.
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.SH APPLICATION USAGE
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.LP
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The \fIsem_unlink\fP() function is part of the Semaphores option and
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need not be available on all implementations.
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.SH RATIONALE
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.LP
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None.
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.SH FUTURE DIRECTIONS
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.LP
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None.
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.SH SEE ALSO
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.LP
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\fIsemctl\fP() , \fIsemget\fP() , \fIsemop\fP()
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, \fIsem_close\fP() , \fIsem_open\fP() , the Base Definitions volume
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of
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IEEE\ Std\ 1003.1-2001, \fI<semaphore.h>\fP
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.SH COPYRIGHT
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Portions of this text are reprinted and reproduced in electronic form
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from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
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-- Portable Operating System Interface (POSIX), The Open Group Base
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Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
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Electrical and Electronics Engineers, Inc and The Open Group. In the
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event of any discrepancy between this version and the original IEEE and
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The Open Group Standard, the original IEEE and The Open Group Standard
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is the referee document. The original Standard can be obtained online at
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http://www.opengroup.org/unix/online.html .
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