SEM_UNLINK(3)              POSIX Programmer's Manual             SEM_UNLINK(3)



PPRROOLLOOGG
       This manual page is part of the POSIX Programmer's Manual.  The OS
       implementation of this interface may differ (consult the corresponding
       OS manual page for details of OS behavior), or the interface may not be
       implemented on OS.

NNAAMMEE
       sem_unlink -- remove a named semaphore

SSYYNNOOPPSSIISS
       #include <semaphore.h>

       int sem_unlink(const char *_n_a_m_e);

DDEESSCCRRIIPPTTIIOONN
       The _s_e_m___u_n_l_i_n_k() function shall remove the semaphore named by the
       string _n_a_m_e.  If the semaphore named by _n_a_m_e is currently referenced by
       other processes, then _s_e_m___u_n_l_i_n_k() shall have no effect on the state of
       the semaphore. If one or more processes have the semaphore open when
       _s_e_m___u_n_l_i_n_k() is called, destruction of the semaphore is postponed until
       all references to the semaphore have been destroyed by calls to
       _s_e_m___c_l_o_s_e(), ___e_x_i_t(), or _e_x_e_c.  Calls to _s_e_m___o_p_e_n() to recreate or
       reconnect to the semaphore refer to a new semaphore after _s_e_m___u_n_l_i_n_k()
       is called. The _s_e_m___u_n_l_i_n_k() call shall not block until all references
       have been destroyed; it shall return immediately.

RREETTUURRNN VVAALLUUEE
       Upon successful completion, the _s_e_m___u_n_l_i_n_k() function shall return a
       value of 0. Otherwise, the semaphore shall not be changed and the
       function shall return a value of -1 and set _e_r_r_n_o to indicate the
       error.

EERRRROORRSS
       The _s_e_m___u_n_l_i_n_k() function shall fail if:

       EEAACCCCEESS Permission is denied to unlink the named semaphore.

       EENNOOEENNTT The named semaphore does not exist.

       The _s_e_m___u_n_l_i_n_k() function may fail if:

       EENNAAMMEETTOOOOLLOONNGG
              The length of the _n_a_m_e argument exceeds {_POSIX_PATH_MAX} on
              systems that do not support the XSI option or exceeds
              {_XOPEN_PATH_MAX} on XSI systems, or has a pathname component
              that is longer than {_POSIX_NAME_MAX} on systems that do not
              support the XSI option or longer than {_XOPEN_NAME_MAX} on XSI
              systems.  A call to _s_e_m___u_n_l_i_n_k() with a _n_a_m_e argument that
              contains the same semaphore name as was previously used in a
              successful _s_e_m___o_p_e_n() call shall not give an [[EENNAAMMEETTOOOOLLOONNGG]]
              error.

       _T_h_e _f_o_l_l_o_w_i_n_g _s_e_c_t_i_o_n_s _a_r_e _i_n_f_o_r_m_a_t_i_v_e_.

EEXXAAMMPPLLEESS
       None.

AAPPPPLLIICCAATTIIOONN UUSSAAGGEE
       None.

RRAATTIIOONNAALLEE
       None.

FFUUTTUURREE DDIIRREECCTTIIOONNSS
       A future version might require the _s_e_m___o_p_e_n() and _s_e_m___u_n_l_i_n_k()
       functions to have semantics similar to normal file system operations.

SSEEEE AALLSSOO
       _s_e_m_c_t_l(), _s_e_m_g_e_t(), _s_e_m_o_p(), _s_e_m___c_l_o_s_e(), _s_e_m___o_p_e_n()

       The Base Definitions volume of POSIX.1-2017, <<sseemmaapphhoorree..hh>>

CCOOPPYYRRIIGGHHTT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  In the event of any discrepancy between this version and the
       original IEEE and The Open Group Standard, the original IEEE and The
       Open Group Standard is the referee document. The original Standard can
       be obtained online at http://www.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .



IEEE/The Open Group                  2017                        SEM_UNLINK(3)
