output-file-atomically v1.0.0

Output File Atomically

Write a file in an atomic fashion and create its ancestor directories if needed.

Installation

npm install --save output-file-atomically

Usage

const outputFileAtomically = require('output-file-atomically')

outputFileAtomically('path/to/file.txt', 'Hello, World!')
  .then(() => console.log('File created!'))

API

outputFileAtomically(filename, data[, options]) => Promise

• filename String
• data String | Buffer
• options Object
  • chown Object
    • uid Number
    • gid Number
  • encoding String | Null default = 'utf8'
  • mode Number default = 438 (aka 0666 in Octal)

Atomically and asynchronously writes data to a file, replacing the file if it already exists. data can be a string or a buffer.

The file is initially named filename + "." + murmurhex(__filename, process.pid, ++invocations). If writeFile completes successfully then, if passed the chown option it will change the ownership of the file. Finally it renames the file back to the filename you specified. If it encounters errors at any of these steps it will attempt to unlink the temporary file and then reject the returned promise.

If provided, the chown option requires both uid and gid properties or else the returned promise will be rejected with an error.

The encoding option is ignored if data is a buffer. It defaults to 'utf8'.