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inotify_add_watch() - Unix, Linux System Call
inotify_add_watch - add a watch to an initialized inotify instance
int inotify_add_watch(int fd, const char *pathname, uint32_t mask);
inotify_add_watch() adds a new watch, or modifies an existing watch,
for the file whose location is specified in
pathname; the caller must have read permission for this file.
fd argument is a file descriptor referring to the
inotify instance whose watch list is to be modified.
The events to be monitored for
pathname are specified in the
mask bit-mask argument.
for a description of the bits that can be set in
A successful call to
inotify_add_watch() returns the unique watch descriptor associated with
pathname for this inotify instance.
pathname was not previously being watched by this inotify instance,
then the watch descriptor is newly allocated.
pathname was already being watched, then the descriptor
for the existing watch is returned.
The watch descriptor is returned by later
from the inotify file descriptor.
These reads fetch
inotify_event structures indicating file system events;
the returned watch descriptor identifies
the object for which the event occurred.
inotify_add_watch() returns a non-negative watch descriptor.
On error -1 is returned and
errno is set appropriately.
Read access to the given file is not permitted.
The given file descriptor is not valid.
pathname points outside of the processs accessible address space.
The given event mask contains no legal events; or
fd is not an inotify file descriptor.
Insufficient kernel memory was available.
The user limit on the total number of inotify watches was reached or the
kernel failed to allocate a needed resource.
Inotify was merged into the 2.6.13 Linux kernel.
This system call is Linux specific.