# string|ArrayBuffer FileSystemManager.readFileSync(string filePath, string encoding, number position, number length)

with Promise style call: Not supported

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

FileSystemManager.readFile The synchronous version of

# parameter

# string filePath

Path to the file to read (Local path)

# string encoding

Specifies the character encoding for the read file, if the Encoding, the ArrayBuffer Format to read the binary contents of a file

encoding Legal value

value Introductions Minimum version
ascii
base64
binary
hex
ucs2 Read in small endorder
ucs-2 Read in small endorder
Utf16le Read in small endorder
utf-16le Read in small endorder
utf-8
utf8
latin1

# number position

Start from base library version 2.10.0. Please remaining backward compatible.

Start reading from the specified location in the file or from the file header if not specified. Read range should be left closed and right open range [position, position+length)。有效范围:[0, fileLength - 1]. Unit: byte

# number length

Start from base library version 2.10.0. Please remaining backward compatible.

Specifies the length of the file, if not specified, read to the end of the document. Scope of validity:[1, fileLength]. Unit: byte

# Return value

# string|ArrayBuffer data

Document content

# error

Error code Error message Introductions
fail No such file or directory, open ${filePath} Specified filePath Directory does not exist
fail permission denied, open ${dirPath} Specified filePath Path not read
fail sdcard not mounted Android sdcard Mount failure

# sample code

const fs = wx.getFileSystemManager()
fs.readFile({
  filePath: `${wx.env.USER_DATA_PATH}/hello.txt`, 
  encoding: 'utf8',
  position: 0,
  success(res) {
    console.log(res.data)
  },
  fail(res) {
    console.error(res)
  }
})

// Synchronous interface
try {
  const res = fs.readFileSync(`${wx.env.USER_DATA_PATH}/hello.txt`,  'utf8', 0)
  console.log(res)
} catch(e) {
  console.error(e)
}