This is psem/psem_getvalue.c (Listing 53-5, page 1098), an example from the book, The Linux Programming Interface.
The source code file is copyright 2022, Michael Kerrisk, and is licensed under the GNU General Public License, version 3.
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In the listing below, the names of Linux system calls and C library functions are hyperlinked to manual pages from the Linux man-pages project, and the names of functions implemented in the book are hyperlinked to the implementations of those functions.
/* psem_getvalue.c Obtain the value of a POSIX named semaphore. On Linux, named semaphores are supported with kernel 2.6 or later, and a glibc that provides the NPTL threading implementation. */ #include <semaphore.h> #include "tlpi_hdr.h"
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