FreeBSD Manual Pages
LIBINOTIFY(3) Library Functions Manual LIBINOTIFY(3) NAME libinotify, inotify_init, inotify_init1, inotify_add_watch, inotify_rm_watch, libinotify_set_param, inotify_event, libinotify_direct_readv, libinotify_free_iovec, libinotify_direct_close, -- monitor file system events SYNOPSIS #include <sys/inotify.h> int inotify_init(); int inotify_init1(int flags); int inotify_add_watch(int fd, const char *pathname, uint32_t mask); int inotify_rm_watch(int fd, int wd); int libinotify_set_param(int fd, int param, intptr_t value); int libinotify_direct_readv(int fd, struct iovec **events, int size, int no_block); void libinotify_free_iovec(struct iovec *events); int libinotify_direct_close(int fd); DESCRIPTION The inotify_init() and inotify_init1() functions create an inotify instance and returns a file descriptor referring to the instance. inotify_init1() function is similar to inotify_init() except that it takes additional flags parameter whose values can be: IN_NONBLOCK Set I_NONBLOCK file status flag on the inotify file de- scriptor. IN_CLOSEXEC Set FD_CLOEXEC flag on the new file descriptor. See O_CLOEXEC flag in open(2) IN_DIRECT libinotify-specific flag that enables direct mode (see below) The function returns the file descritor to the inotify handle if successful otherwise return -1. Possible errorno values are - EINVAL Invalid flag value passed. EMFILE System wide limit of inotify instances reached. ENFILE System limit on total number of fd's reached. ENOMEM Insufficient kernel memory. inotify_add_watch() function adds news watch to the inotify instance. List of possible masks are described below. If the watch for given filename al- ready exists, it it updated with the new mask value passed. The function returns an integer called watch descriptor if successful otherwise -1. Possible values for errorno are - EACCES Permission for read access is denied for given file. EBADF Invalid file descriptor. EFAULT Pathname points outside process's allocated address space. EINVAL Invalid event mask passed. ENOENT A component of path that must exist does not exist. ENOMEM Insufficient kernel memory available. ENOSPC User limit on total number of inotify watches has crossed or kernel failed to allocate a needed resource. inotify_rm_watch() function removes watch wd from the instance described by file descriptor fd. The function returns zero on sucess and -1 on error. Possible errorno values are - EBADF Invalid file descriptor fd. EINVAL Invalid watch descriptor wd. libinotify_set_param() Libinotify specific. Replacement for Linux procfs interface. Set inotify parameter for the instance described by file de- scriptor fd. fd value of -1 is used for setting of global parameters. Pos- sible param values are - IN_SOCKBUFSIZE Size of communication socket buffer in bytes. Should match read(2) buffer size for libinotify event con- sumers. Lower values can cause partial event reads. Bigger values is just a wasting of memory. Default value is arbitrary, has been acquired from code sample in linux inotify(7) man page and seems to be very common among the inotify clients. Default value 4096 (exported as IN_DEF_SOCKBUFSIZE) IN_MAX_QUEUED_EVENTS Upper limit on the queue length per inotify handle. linux`s /proc/sys/fs/inotify/max_queued_events counter- part. Default value 16384 (exported as IN_DEF_MAX_QUEUED_EVENTS) IN_MAX_USER_INSTANCES Global upper limit on the number of inotify instances that can be created. linux`s /proc/sys/fs/ino- tify/max_user_instances counterpart. Default value 2147483646 (exported as IN_DEF_MAX_USER_INSTANCES) inotify_event structure struct inotify_event { int wd; /* Watch descriptor */ uint32_t mask; /* Mask of events */ uint32_t cookie; /* Unique integer associating related events */ uint32_t len; /* Size of name field */ char name[]; /* Optional null-terminated name */ }; inotify events - Following are the masks supported by libinotify implementation. IN_OPEN File was opened. IN_ACCESS File was accessed (read). IN_ATTRIB Metadata changed. IN_CREATE File/directory was created in watched directory. IN_CLOSE_WRITE File opened for writing was closed. IN_CLOSE_NOWRITE File not opened for writing was closed. IN_DELETE File/directory in watched directory was deleted. IN_DELETE_SELF Watched file/directory was deleted. IN_MODIFY File/Directory was modified. IN_MOVE_SELF Watched file/directory was moved. IN_MOVED_FROM A file in watched directory was moved out. IN_MOVED_TO A file was moved into watched directory. IN_ALL_EVENTS Bit mask of all the above events. IN_MOVE Equal to IN_MOVED_FROM|IN_MOVED_TO IN_CLOSE Equal to IN_CLOSE_WRITE|IN_CLOSE_NOWRITE IN_DELETE_SELF and IN_MOVE_SELF can occur only for watched file/directory. Other events can be marked for a file/directory in a watched direcotry. In that case the name of the file for which event is generated can be read by 'name' field in inotify_event structure. Following are additional bits that can be set in mask when calling inotify_add_watch() - IN_DONT_FOLLOW Don't derefernce path name if its symlink. IN_EXCL_UNLINK Do not generate events for unlinked childrens. (Cur- rently not supported). IN_MASK_ADD Add event mask for watch for given pathname. IN_ONESHOT Remove watch after retrieving one event. IN_ONLYDIR Only watch the pathname if it is a directory. Following bits may be set by mask field returned by read(3) IN_IGNORED Watch for removed (explicitely, revoked or unmounted). IN_ISDIR Subject of this event is a directory. IN_Q_OVERFLOW Event queue has overflowed. IN_UNMOUNT File system containing watched file/directory was un- mounted. DIRECT MODE In this mode the fd handed over to the user isn't a read()able one, but is actually a kqueue fd. This allows to reduce some copying overhead at the cost of being incompatible with how Linux inotify fd works. The mode is activated by passing IN_DIRECT to inotify_init1(). libinotify_direct_readv() is a replacement for the read call in direct mode. Pass it an array of struct iovec* of desired size to fill it with lists of events. Each struct iovec* points to an array of structs termi- nated with a null iovec (iov_base = NULL). It is the caller responsibility to free these arrays. libinotify_free_iovec() Frees a list of iovec structs returned by the pre- vious call. libinotify_direct_close() is a replacement for the close call in direct mode. SEE ALSO read(3) HISTORY inotify first appeared in Linux 2.6.13 FreeBSD ports 15.quarterly July 22, 2024 LIBINOTIFY(3)
NAME | SYNOPSIS | DESCRIPTION | inotify_event structure | inotify events - | DIRECT MODE | SEE ALSO | HISTORY
Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=libinotify_set_param&sektion=3&manpath=FreeBSD+Ports+15.1.quarterly>