tildefriends/deps/libuv/docs/src/fs_poll.rst

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.. _fs_poll:
:c:type:`uv_fs_poll_t` --- FS Poll handle
=========================================
FS Poll handles allow the user to monitor a given path for changes. Unlike
:c:type:`uv_fs_event_t`, fs poll handles use `stat` to detect when a file has
changed so they can work on file systems where fs event handles can't.
Data types
----------
.. c:type:: uv_fs_poll_t
FS Poll handle type.
.. c:type:: void (*uv_fs_poll_cb)(uv_fs_poll_t* handle, int status, const uv_stat_t* prev, const uv_stat_t* curr)
Callback passed to :c:func:`uv_fs_poll_start` which will be called repeatedly
after the handle is started, when any change happens to the monitored path.
The callback is invoked with `status < 0` if `path` does not exist
or is inaccessible. The watcher is *not* stopped but your callback is
not called again until something changes (e.g. when the file is created
or the error reason changes).
When `status == 0`, the callback receives pointers to the old and new
:c:type:`uv_stat_t` structs. They are valid for the duration of the
callback only.
Public members
^^^^^^^^^^^^^^
N/A
.. seealso:: The :c:type:`uv_handle_t` members also apply.
API
---
.. c:function:: int uv_fs_poll_init(uv_loop_t* loop, uv_fs_poll_t* handle)
Initialize the handle.
.. c:function:: int uv_fs_poll_start(uv_fs_poll_t* handle, uv_fs_poll_cb poll_cb, const char* path, unsigned int interval)
Check the file at `path` for changes every `interval` milliseconds.
.. note::
For maximum portability, use multi-second intervals. Sub-second intervals will not detect
all changes on many file systems.
.. c:function:: int uv_fs_poll_stop(uv_fs_poll_t* handle)
Stop the handle, the callback will no longer be called.
.. c:function:: int uv_fs_poll_getpath(uv_fs_poll_t* handle, char* buffer, size_t* size)
Get the path being monitored by the handle. The buffer must be preallocated
by the user. Returns 0 on success or an error code < 0 in case of failure.
On success, `buffer` will contain the path and `size` its length. If the buffer
is not big enough `UV_ENOBUFS` will be returned and `size` will be set to
the required size.
.. versionchanged:: 1.3.0 the returned length no longer includes the terminating null byte,
and the buffer is not null terminated.
.. versionchanged:: 1.9.0 the returned length includes the terminating null
byte on `UV_ENOBUFS`, and the buffer is null terminated
on success.
.. seealso:: The :c:type:`uv_handle_t` API functions also apply.