INOTIFY_ADD_WATCH(2) Linux Programmer's Manual INOTIFY_ADD_WATCH(2)

inotify_add_watch - add a watch to an initialized inotify instance

#include <inotify.h>

int inotify_add_watch(int fd, const char *path, uint32_t mask);

inotify_add_watch() adds a watch on the file at pathname path to the inotify instance mapped by the file descriptor fd with the event mask given by the bitmask mask. See inotify(7) for a description of the bits that can be set in mask.

A successful call to inotify_add_watch() returns the unique watch descriptor associated with path for this inotify instance. If path was not previously being watched by this inotify instance, then the watch descriptor is newly allocated. If path was already being watched, then the descriptor for the existing watch is returned.

The watch descriptor is returned by later read(2)s 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.

On success, 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.
path points outside of the process's accessible address space.
The given event mask contains no legal events.
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.

In kernels before 2.6.16, the IN_ONESHOT mask flag does not work.

inotify_init(2), inotify_rm_watch(2), inotify(7).

2006-02-07 Linux

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