# FileSystemManager.open(Object object)

Start from base library version 2.16.1. Please remaining backward compatible.

with Promise style call: Not supported

Mini Program plugin: Support, need to Mini Program base library version no less than 2.19.2

Open the file and return the file descriptor

# parameter

# Object object

attribute	type	Default values	Required	Introductions
filePath	string		yes	File path (Local path)
flag	string	r	no	File system flag, default: 'r'
success	function		no	Interface calls the successful callback function
fail	function		no	Interface calls failed callback functions
complete	function		no	Callback function at the end of an interface call (both successful and unsuccessful calls are executed)

object.flag Legal value

value	Introductions	Minimum version
a	Open the file for appending. If the file does not exist, create the file
ax	Similar to 'a ', but fails if path exists
a+	Open the file for reading and appending. If the file does not exist, create the file
ax+	Similar to 'a + ', but fails if path exists
as	Open the file for appending (in sync mode). If the file does not exist, create the file
as+	Open files for reading and appending (in synchronous mode). If the file does not exist, create the file
r	Open the file for reading. If the file does not exist, an exception occurs
r+	Open files for reading and writing. If the file does not exist, an exception occurs
初始值	Open the file for writing. Create a file if it does not exist, and truncate it if it exists
wx	Similar to 'w ', but fails if path exists
w+	Open files for reading and writing. Create a file if it does not exist, and truncate it if it exists
wx+	Similar to 'w + ', but fails if path exists

# object.success callback

# parameter

# Object res

attribute	type	Introductions
fd	string	File descriptor

# object.fail callback

# parameter

# Object res

attribute	type	Introductions
errMsg	string	Error message

res.errMsg Legal value

value	Introductions	Minimum version
fail No such file or directory "${filePath}"	There is no parent directory

# sample code

const fs = wx.getFileSystemManager()
fs.open({
  filePath: `${wx.env.USER_DATA_PATH}/hello.txt`, 
  flag: 'a+',
  success(res) {
    console.log(res.fd)
  }
})