NAME¶
inotify_add_watch - add a watch to an initialized inotify instance
SYNOPSIS¶
#include <sys/inotify.h>
int inotify_add_watch(int fd, const char
*pathname, uint32_t mask);
DESCRIPTION¶
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. The
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. 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
pathname for this inotify instance. If
pathname was not previously being watched by this inotify instance,
then the watch descriptor is newly allocated. If
pathname 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 (see
inotify(7)) indicating file system events; the watch descriptor inside
this structure identifies the object for which the event occurred.
RETURN VALUE¶
On success,
inotify_add_watch() returns a nonnegative watch descriptor.
On error -1 is returned and
errno is set appropriately.
ERRORS¶
- EACCES
- Read access to the given file is not permitted.
- EBADF
- The given file descriptor is not valid.
- EFAULT
- pathname points outside of the process's accessible
address space.
- EINVAL
- The given event mask contains no valid events; or fd
is not an inotify file descriptor.
- ENOENT
- A directory component in pathname does not exist or
is a dangling symbolic link.
- ENOMEM
- Insufficient kernel memory was available.
- ENOSPC
- The user limit on the total number of inotify watches was
reached or the kernel failed to allocate a needed resource.
VERSIONS¶
Inotify was merged into the 2.6.13 Linux kernel.
This system call is Linux-specific.
SEE ALSO¶
inotify_init(2),
inotify_rm_watch(2),
inotify(7)
COLOPHON¶
This page is part of release 3.44 of the Linux
man-pages project. A
description of the project, and information about reporting bugs, can be found
at
http://www.kernel.org/doc/man-pages/.