inotify_add_watch()

Synopsis:

#include <sys/inotify.h>

int inotify_add_watch( int fd,
                       const char *pathname,
                       int mask );

Arguments:

fd

A valid file descriptor returned by inotify_init().

path

The path whose filesystem events you want to monitor.

mask

A bitmask that specifies the events you want to watch. The bits include:

IN_ACCESS — the file was read.
IN_MODIFY — the file was written to.
IN_ATTRIB — the attributes of the file changed.
IN_CLOSE_WRITE — a file that was opened for writing was closed.
IN_CLOSE_NOWRITE — a file that was opened not for writing was closed.
IN_CLOSE — the same as (IN_CLOSE_WRITE | IN_CLOSE_NOWRITE).
IN_OPEN — the file was opened.
IN_MOVED_FROM — the file was moved or renamed away from the item being watched.
IN_MOVED_TO — the file was moved or renamed to the item being watched.
IN_MOVE — the same as (IN_MOVED_FROM | IN_MOVED_TO).
IN_CREATE — a file was created in a watched directory.
IN_DELETE — a file or directory was deleted.
IN_DELETE_SELF — the file or directory being monitored was deleted.
IN_MOVE_SELF — the file or directory being monitored was moved or renamed.

IN_ALL_EVENTS is a bitwise-OR of all the event types.

You can OR the following into the event type:

IN_ONESHOT — remove the watch during the generation of the first event.
IN_ONLYDIR — watch the pathname only if it's a directory.
IN_DONT_FOLLOW — don't dereference the pathname if it's a symbolic link.
IN_EXCL_UNLINK — don't generate events for children after they've been unlinked from the watched directory.
IN_MASK_ADD — add events to the watch mask (if one already exists) for this pathname, instead of replacing it.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The inotify_add_watch() function starts watching for filesystem events associated with the given path. For you to use this function, the filesystem event manager (fsevmgr) manager needs to be running.

Note: By default, inotify events are non-recursive, so you have to create a specific watch for each file or directory that you want to watch.

For an overview of inotify, see http://www.linuxjournal.com/article/8478?page=0,0 in the Linux Journal, but note that there are differences between the Linux and QNX Neutrino implementations. Currently, only io-blk.so-based filesystems support inotify.

Returns:

A watch descriptor, or -1 if an error occurred (errno is set).

Classification:

Linux

Safety:
Cancellation point	Yes
Interrupt handler	No
Signal handler	No
Thread	Yes