Does anyone know what the file descriptor 'fd' pointer does? My module makes
a system call [sys_open] to the kernal which then returns a fd value but I
don't know what this value means or how it gets it. Does the fd value
signify a specific device or is it random? Any ideas?
Thanks for your help in advance.
-Nav
* Nav Mundi ([email protected]) wrote:
> Does anyone know what the file descriptor 'fd' pointer does? My module makes
> a system call [sys_open] to the kernal which then returns a fd value but I
> don't know what this value means or how it gets it. Does the fd value
> signify a specific device or is it random? Any ideas?
fd is a handle for the kernel file struct representing the file you
opened. read include/linux/file.h::fd_install() to understand where
it's put, and include/linux/file.h::fcheck() as an example of retrieving
kernel object from the handle.
cheers,
-chris