1SEM_UNLINK(3P) POSIX Programmer's Manual SEM_UNLINK(3P)
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6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
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13 sem_unlink — remove a named semaphore
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16 #include <semaphore.h>
17 int sem_unlink(const char *name);
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21 The sem_unlink() function shall remove the semaphore named by the
22 string name. If the semaphore named by name is currently referenced by
23 other processes, then sem_unlink() shall have no effect on the state of
24 the semaphore. If one or more processes have the semaphore open when
25 sem_unlink() is called, destruction of the semaphore is postponed until
26 all references to the semaphore have been destroyed by calls to
27 sem_close(), _exit(), or exec. Calls to sem_open() to recreate or
28 reconnect to the semaphore refer to a new semaphore after sem_unlink()
29 is called. The sem_unlink() call shall not block until all references
30 have been destroyed; it shall return immediately.
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33 Upon successful completion, the sem_unlink() function shall return a
34 value of 0. Otherwise, the semaphore shall not be changed and the func‐
35 tion shall return a value of −1 and set errno to indicate the error.
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38 The sem_unlink() function shall fail if:
39 EACCES Permission is denied to unlink the named semaphore.
41 ENOENT The named semaphore does not exist.
43 The sem_unlink() function may fail if:
45 ENAMETOOLONG
47 The length of the name argument exceeds {_POSIX_PATH_MAX} on
48 systems that do not support the XSI option or exceeds
49 {_XOPEN_PATH_MAX} on XSI systems, or has a pathname component
50 that is longer than {_POSIX_NAME_MAX} on systems that do not
51 support the XSI option or longer than {_XOPEN_NAME_MAX} on XSI
52 systems. A call to sem_unlink() with a name argument that con‐
53 tains the same semaphore name as was previously used in a suc‐
54 cessful sem_open() call shall not give an [ENAMETOOLONG] error.
55 The following sections are informative.
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59 None.
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62 None.
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65 None.
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68 A future version might require the sem_open() and sem_unlink() func‐
69 tions to have semantics similar to normal file system operations.
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72 semctl(), semget(), semop(), sem_close(), sem_open()
73 The Base Definitions volume of POSIX.1‐2008, <semaphore.h>
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77 Portions of this text are reprinted and reproduced in electronic form
78 from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
79 -- Portable Operating System Interface (POSIX), The Open Group Base
80 Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
81 cal and Electronics Engineers, Inc and The Open Group. (This is
82 POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
83 event of any discrepancy between this version and the original IEEE and
84 The Open Group Standard, the original IEEE and The Open Group Standard
85 is the referee document. The original Standard can be obtained online
86 at http://www.unix.org/online.html .
87 Any typographical or formatting errors that appear in this page are
89 most likely to have been introduced during the conversion of the source
90 files to man page format. To report such errors, see https://www.ker‐
91 nel.org/doc/man-pages/reporting_bugs.html .
92IEEE/The Open Group 2013 SEM_UNLINK(3P)