01-26-2004
file descriptors
i m trying to learn processes in unix and i've been reading this but i don't quite get it. its regarding file descriptors. : each is a part of file pointers, they point to another area. indexes into an Operating system maintained table called "file descriptor table". one table per process. may contain 20 entries called file pointers which point to an area of memory containing info about the opening of the file.
can someone comment on that, please!
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LEARN ABOUT HPUX
sem_destroy
sem_destroy(2) System Calls Manual sem_destroy(2)
NAME
sem_destroy - destroy an unnamed POSIX semaphore
SYNOPSIS
DESCRIPTION
is used to destroy an unnamed semaphore. A successful call to will invalidate the unnamed semaphore referred to by sem and removes all
descriptors referencing it. The semaphore should have been created by a previous call to and there should not be any processes blocked on
it.
To use this function, link in the realtime library by specifying on the compiler or linker command line.
EXAMPLES
The following call to will destroy an unnamed semaphore referred to by sem and remove all descriptors referencing it.
RETURN VALUE
If the semaphore was destroyed and the descriptors referencing it were removed, returns 0 to the caller.
If the semaphore could not be destroyed, the call returns -1 and sets to indicate the error.
ERRORS
fails and does not perform the requested operation if any of the following conditions are encountered:
[EBUSY] There are threads currently blocked on the semaphore or there are outstanding locks held on the semaphore.
[EINVAL] The argument sem is not a valid unnamed semaphore.
SEE ALSO
sem_init(2), sem_open(2), <semaphore.h>.
STANDARDS CONFORMANCE
sem_destroy(2)