diff --git a/docs/en/modules/file.md b/docs/en/modules/file.md
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+++ b/docs/en/modules/file.md
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+# file Module
+| Since  | Origin / Contributor  | Maintainer  | Source  |
+| :----- | :-------------------- | :---------- | :------ |
+| 2014-12-22 | [Zeroday](https://github.com/funshine) | [Zeroday](https://github.com/funshine) | [file.c](../../../app/modules/file.c)|
+
+The file module provides access to the file system and its individual files.
+
+The file system is a flat file system, with no notion of subdirectories/folders.
+
+Only one file can be open at any given time.
+
+Besides the SPIFFS file system on internal flash, this module can also access FAT partitions on an external SD card is [FatFS is enabled](../sdcard.md).
+
+```lua
+-- open file in flash:
+if file.open("init.lua") then
+  print(file.read())
+  file.close()
+end
+
+-- or with full pathspec
+file.open("/FLASH/init.lua")
+
+-- open file on SD card
+if file.open("/SD0/somefile.txt") then
+  print(file.read())
+  file.close()
+end
+```
+
+## file.chdir()
+
+Change current directory (and drive). This will be used when no drive/directory is prepended to filenames.
+
+Current directory defaults to the root of internal SPIFFS (`/FLASH`) after system start.
+
+#### Syntax
+`file.chdir(dir)`
+
+#### Parameters
+`dir` directory name - `/FLASH`, `/SD0`, `/SD1`, etc.
+
+#### Returns
+`true` on success, `false` otherwise
+
+## file.close()
+
+Closes the open file, if any.
+
+#### Syntax
+`file.close()`
+
+#### Parameters
+none
+
+#### Returns
+`nil`
+
+#### Example
+```lua
+-- open 'init.lua', print the first line.
+if file.open("init.lua", "r") then
+  print(file.readline())
+  file.close()
+end
+```
+#### See also
+[`file.open()`](#fileopen)
+
+## file.exists()
+
+Determines whether the specified file exists.
+
+#### Syntax
+`file.exists(filename)`
+
+#### Parameters
+- `filename` file to check
+
+#### Returns
+true of the file exists (even if 0 bytes in size), and false if it does not exist
+
+#### Example
+
+```lua
+files = file.list()
+if files["device.config"] then
+    print("Config file exists")
+end
+
+if file.exists("device.config") then
+    print("Config file exists")
+end
+```
+#### See also
+[`file.list()`](#filelist)
+
+## file.flush()
+
+Flushes any pending writes to the file system, ensuring no data is lost on a restart. Closing the open file using [`file.close()`](#fileclose) performs an implicit flush as well.
+
+#### Syntax
+`file.flush()`
+
+#### Parameters
+none
+
+#### Returns
+`nil`
+
+#### Example
+```lua
+-- open 'init.lua' in 'a+' mode
+if file.open("init.lua", "a+") then
+  -- write 'foo bar' to the end of the file
+  file.write('foo bar')
+  file.flush()
+  -- write 'baz' too
+  file.write('baz')
+  file.close()
+end
+```
+#### See also
+[`file.close()`](#fileclose)
+
+## file.format()
+
+Format the file system. Completely erases any existing file system and writes a new one. Depending on the size of the flash chip in the ESP, this may take several seconds.
+
+Not supported for SD cards.
+
+#### Syntax
+`file.format()`
+
+#### Parameters
+none
+
+#### Returns
+`nil`
+
+#### See also
+[`file.remove()`](#fileremove)
+
+## file.fscfg ()
+
+Returns the flash address and physical size of the file system area, in bytes.
+
+Not supported for SD cards.
+
+#### Syntax
+`file.fscfg()`
+
+#### Parameters
+none
+
+#### Returns
+- `flash address` (number)
+- `size` (number)
+
+#### Example
+```lua
+print(string.format("0x%x", file.fscfg()))
+```
+
+## file.fsinfo()
+
+Return size information for the file system. The unit is Byte for SPIFFS and kByte for FatFS.
+
+#### Syntax
+`file.fsinfo()`
+
+#### Parameters
+none
+
+#### Returns
+- `remaining` (number)
+- `used`      (number)
+- `total`     (number)
+
+#### Example
+
+```lua
+-- get file system info
+remaining, used, total=file.fsinfo()
+print("\nFile system info:\nTotal : "..total.." (k)Bytes\nUsed : "..used.." (k)Bytes\nRemain: "..remaining.." (k)Bytes\n")
+```
+
+## file.list()
+
+Lists all files in the file system.
+
+#### Syntax
+`file.list()`
+
+#### Parameters
+none
+
+#### Returns
+a lua table which contains the {file name: file size} pairs
+
+#### Example
+```lua
+l = file.list();
+for k,v in pairs(l) do
+  print("name:"..k..", size:"..v)
+end
+```
+
+## file.mount()
+
+Mounts a FatFs volume on SD card.
+
+Not supported for internal flash.
+
+#### Syntax
+`file.mount(ldrv[, pin])`
+
+#### Parameters
+- `ldrv` name of the logical drive, `SD0:`, `SD1:`, etc.
+- `pin` 1~12, IO index for SS/CS, defaults to 8 if omitted.
+
+#### Returns
+Volume object
+
+#### Example
+```lua
+vol = file.mount("SD0:")
+vol:umount()
+```
+
+## file.on()
+
+Registers callback functions.
+
+Trigger events are:
+- `rtc` deliver current date & time to the file system. Function is expected to return a table containing the fields `year`, `mon`, `day`, `hour`, `min`, `sec` of current date and time. Not supported for internal flash.
+
+#### Syntax
+`file.on(event[, function()])`
+
+#### Parameters
+- `event` string
+- `function()` callback function. Unregisters the callback if `function()` is omitted.
+
+#### Returns
+`nil`
+
+#### Example
+```lua
+sntp.sync(server_ip,
+  function()
+    print("sntp time sync ok")
+    file.on("rtc",
+      function()
+        return rtctime.epoch2cal(rtctime.get())
+      end)
+  end)
+```
+
+#### See also
+[`rtctime.epoch2cal()`](rtctime.md#rtctimepoch2cal)
+
+## file.open()
+
+Opens a file for access, potentially creating it (for write modes).
+
+When done with the file, it must be closed using `file.close()`.
+
+#### Syntax
+`file.open(filename, mode)`
+
+#### Parameters
+- `filename` file to be opened, directories are not supported
+- `mode`:
+    - "r": read mode (the default)
+    - "w": write mode
+    - "a": append mode
+    - "r+": update mode, all previous data is preserved
+    - "w+": update mode, all previous data is erased
+    - "a+": append update mode, previous data is preserved, writing is only allowed at the end of file
+
+#### Returns
+`nil` if file not opened, or not exists (read modes).  `true` if file opened ok.
+
+#### Example
+```lua
+-- open 'init.lua', print the first line.
+if file.open("init.lua", "r") then
+  print(file.readline())
+  file.close()
+end
+```
+#### See also
+- [`file.close()`](#fileclose)
+- [`file.readline()`](#filereadline)
+
+## file.read()
+
+Read content from the open file.
+
+#### Syntax
+`file.read([n_or_str])`
+
+#### Parameters
+- `n_or_str`:
+	- if nothing passed in, read up to `LUAL_BUFFERSIZE` bytes (default 1024) or the entire file (whichever is smaller)
+	- if passed a number n, then read the file until the lesser of `n` bytes, `LUAL_BUFFERSIZE` bytes, or EOF is reached. Specifying a number larger than the buffer size will read the buffer size.
+	- if passed a string `str`, then read until `str` appears next in the file, `LUAL_BUFFERSIZE` bytes have been read, or EOF is reached
+
+#### Returns
+File content as a string, or nil when EOF
+
+#### Example
+```lua
+-- print the first line of 'init.lua'
+if file.open("init.lua", "r") then
+  print(file.read('\n'))
+  file.close()
+end
+
+-- print the first 5 bytes of 'init.lua'
+if file.open("init.lua", "r") then
+  print(file.read(5))
+  file.close()
+end
+```
+
+#### See also
+- [`file.open()`](#fileopen)
+- [`file.readline()`](#filereadline)
+
+## file.readline()
+
+Read the next line from the open file. Lines are defined as zero or more bytes ending with a EOL ('\n') byte. If the next line is longer than `LUAL_BUFFERSIZE`, this function only returns the first `LUAL_BUFFERSIZE` bytes (this is 1024 bytes by default).
+
+#### Syntax
+`file.readline()`
+
+#### Parameters
+none
+
+#### Returns
+File content in string, line by line, including EOL('\n'). Return `nil` when EOF.
+
+#### Example
+```lua
+-- print the first line of 'init.lua'
+if file.open("init.lua", "r") then
+  print(file.readline())
+  file.close()
+end
+```
+#### See also
+- [`file.open()`](#fileopen)
+- [`file.close()`](#fileclose)
+- [`file.read()`](#filereade)
+
+## file.remove()
+
+Remove a file from the file system. The file must not be currently open.
+
+###Syntax
+`file.remove(filename)`
+
+#### Parameters
+`filename` file to remove
+
+#### Returns
+`nil`
+
+#### Example
+
+```lua
+-- remove "foo.lua" from file system.
+file.remove("foo.lua")
+```
+#### See also
+[`file.open()`](#fileopen)
+
+## file.rename()
+
+Renames a file. If a file is currently open, it will be closed first.
+
+#### Syntax
+`file.rename(oldname, newname)`
+
+#### Parameters
+- `oldname` old file name
+- `newname` new file name
+
+#### Returns
+`true` on success, `false` on error.
+
+#### Example
+
+```lua
+-- rename file 'temp.lua' to 'init.lua'.
+file.rename("temp.lua","init.lua")
+```
+
+## file.seek()
+Sets and gets the file position, measured from the beginning of the file, to the position given by offset plus a base specified by the string whence.
+
+#### Syntax
+`file.seek([whence [, offset]])`
+
+#### Parameters
+- `whence`
+	- "set": base is position 0 (beginning of the file)
+	- "cur": base is current position (default value)
+	- "end": base is end of file
+- `offset` default 0
+
+If no parameters are given, the function simply returns the current file offset.
+
+#### Returns
+the resulting file position, or `nil` on error
+
+#### Example
+```lua
+if file.open("init.lua", "r") then
+  -- skip the first 5 bytes of the file
+  file.seek("set", 5)
+  print(file.readline())
+  file.close()
+end
+```
+#### See also
+[`file.open()`](#fileopen)
+
+## file.write()
+
+Write a string to the open file.
+
+#### Syntax
+`file.write(string)`
+
+#### Parameters
+`string` content to be write to file
+
+#### Returns
+`true` if the write is ok, `nil` on error
+
+#### Example
+```lua
+-- open 'init.lua' in 'a+' mode
+if file.open("init.lua", "a+") then
+  -- write 'foo bar' to the end of the file
+  file.write('foo bar')
+  file.close()
+end
+```
+
+#### See also
+- [`file.open()`](#fileopen)
+- [`file.writeline()`](#filewriteline)
+
+## file.writeline()
+
+Write a string to the open file and append '\n' at the end.
+
+#### Syntax
+`file.writeline(string)`
+
+#### Parameters
+`string` content to be write to file
+
+#### Returns
+`true` if write ok, `nil` on error
+
+#### Example
+```lua
+-- open 'init.lua' in 'a+' mode
+if file.open("init.lua", "a+") then
+  -- write 'foo bar' to the end of the file
+  file.writeline('foo bar')
+  file.close()
+end
+```
+
+#### See also
+- [`file.open()`](#fileopen)
+- [`file.readline()`](#filereadline)
diff --git a/mkdocs.yml b/mkdocs.yml
index 29a387b2..f3bdea0d 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -30,5 +30,6 @@ pages:
         - Extension Developer FAQ: 'en/extn-developer-faq.md'
     - Support: 'en/support.md'
     - Modules:
+        - 'file': 'en/modules/file.md'
         - 'node': 'en/modules/node.md'
         - 'uart': 'en/modules/uart.md'