1 2.. _fs_poll: 3 4:c:type:`uv_fs_poll_t` --- FS Poll handle 5========================================= 6 7FS Poll handles allow the user to monitor a given path for changes. Unlike 8:c:type:`uv_fs_event_t`, fs poll handles use `stat` to detect when a file has 9changed so they can work on file systems where fs event handles can't. 10 11 12Data types 13---------- 14 15.. c:type:: uv_fs_poll_t 16 17 FS Poll handle type. 18 19.. c:type:: void (*uv_fs_poll_cb)(uv_fs_poll_t* handle, int status, const uv_stat_t* prev, const uv_stat_t* curr) 20 21 Callback passed to :c:func:`uv_fs_poll_start` which will be called repeatedly 22 after the handle is started, when any change happens to the monitored path. 23 24 The callback is invoked with `status < 0` if `path` does not exist 25 or is inaccessible. The watcher is *not* stopped but your callback is 26 not called again until something changes (e.g. when the file is created 27 or the error reason changes). 28 29 When `status == 0`, the callback receives pointers to the old and new 30 :c:type:`uv_stat_t` structs. They are valid for the duration of the 31 callback only. 32 33 34Public members 35^^^^^^^^^^^^^^ 36 37N/A 38 39.. seealso:: The :c:type:`uv_handle_t` members also apply. 40 41 42API 43--- 44 45.. c:function:: int uv_fs_poll_init(uv_loop_t* loop, uv_fs_poll_t* handle) 46 47 Initialize the handle. 48 49.. c:function:: int uv_fs_poll_start(uv_fs_poll_t* handle, uv_fs_poll_cb poll_cb, const char* path, unsigned int interval) 50 51 Check the file at `path` for changes every `interval` milliseconds. 52 53 .. note:: 54 For maximum portability, use multi-second intervals. Sub-second intervals will not detect 55 all changes on many file systems. 56 57.. c:function:: int uv_fs_poll_stop(uv_fs_poll_t* handle) 58 59 Stop the handle, the callback will no longer be called. 60 61.. c:function:: int uv_fs_poll_getpath(uv_fs_poll_t* handle, char* buffer, size_t* size) 62 63 Get the path being monitored by the handle. The buffer must be preallocated 64 by the user. Returns 0 on success or an error code < 0 in case of failure. 65 On success, `buffer` will contain the path and `size` its length. If the buffer 66 is not big enough `UV_ENOBUFS` will be returned and `size` will be set to 67 the required size. 68 69 .. versionchanged:: 1.3.0 the returned length no longer includes the terminating null byte, 70 and the buffer is not null terminated. 71 72 .. versionchanged:: 1.9.0 the returned length includes the terminating null 73 byte on `UV_ENOBUFS`, and the buffer is null terminated 74 on success. 75 76 77.. seealso:: The :c:type:`uv_handle_t` API functions also apply. 78