inotify_init, inotify_init1 — initialize an inotify instance


#include <sys/inotify.h>

int inotify_init(void);
int inotify_init1(int flags);


For an overview of the inotify API, see inotify(7).

inotify_init() initializes a new inotify instance and returns a file descriptor associated with a new inotify event queue.

If flags is 0, then inotify_init1() is the same as inotify_init(). The following values can be bitwise ORed in flags to obtain different behavior:


Set the O_NONBLOCK file status flag on the open file description (see open(2)) referred to by the new file descriptor. Using this flag saves extra calls to fcntl(2) to achieve the same result.


Set the close-on-exec (FD_CLOEXEC) flag on the new file descriptor. See the description of the O_CLOEXEC flag in open(2) for reasons why this may be useful.

Return Value

On success, these system calls return a new file descriptor. On error, -1 is returned, and errno is set to indicate the error.



(inotify_init1()) An invalid value was specified in flags.


The user limit on the total number of inotify instances has been reached.


The per-process limit on the number of open file descriptors has been reached.


The system-wide limit on the total number of open files has been reached.


Insufficient kernel memory is available.


inotify_init() first appeared in Linux 2.6.13; library support was added to glibc in version 2.4. inotify_init1() was added in Linux 2.6.27; library support was added to glibc in version 2.9.

Conforming to

These system calls are Linux-specific.

See Also

inotify_add_watch(2), inotify_rm_watch(2), inotify(7)


This page is part of release 5.04 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at

Referenced By

inotify(7), inotify_add_watch(2), inotify_rm_watch(2), proc(5), syscalls(2).

The man page inotify_init1(2) is an alias of inotify_init(2).

2019-03-06 Linux Programmer's Manual