Write data to a file.
npm install @stdlib/fs-write-fileAlternatively,
- To load the package in a website via a
scripttag without installation and bundlers, use the ES Module available on theesmbranch. - If you are using Deno, visit the
denobranch. - For use in Observable, or in browser/node environments, use the Universal Module Definition (UMD) build available on the
umdbranch. - To use as a general utility for the command line, install the corresponding CLI package globally.
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var writeFile = require( '@stdlib/fs-write-file' );Asynchronously write data to a file.
var join = require( 'path' ).join;
var fpath = join( __dirname, 'examples', 'fixtures', 'file.txt' );
writeFile( fpath, 'beep boop\n', onWrite );
function onWrite( error ) {
if ( error ) {
throw error;
}
}The data argument may be either a string or a Buffer.
var join = require( 'path' ).join;
var string2buffer = require( '@stdlib/buffer-from-string' );
var fpath = join( __dirname, 'examples', 'fixtures', 'file.txt' );
writeFile( fpath, string2buffer( 'beep boop\n' ), onWrite );
function onWrite( error ) {
if ( error ) {
throw error;
}
}The function accepts the same options and has the same defaults as fs.writeFile().
Synchronously writes data to a file.
var join = require( 'path' ).join;
var fpath = join( __dirname, 'examples', 'fixtures', 'file.txt' );
var err = writeFile.sync( fpath, 'beep boop\n' );
if ( err instanceof Error ) {
throw err;
}The function accepts the same options and has the same defaults as fs.writeFileSync().
-
The difference between this
writeFile.syncandfs.writeFileSync()is thatfs.writeFileSync()will throw if anerroris encountered (e.g., if given a non-existent directory path) and this API will return anerror. Hence, the following anti-patternvar fs = require( 'fs' ); // Check for directory path existence to prevent an error being thrown... if ( fs.existsSync( '/path/to' ) ) { fs.writeFileSync( '/path/to/file.txt', 'beep boop\n' ); }
can be replaced by an approach which addresses existence via
errorhandling.var writeFile = require( '@stdlib/fs-write-file' ); // Explicitly handle the error... var err = writeFile.sync( '/path/to/file.txt', 'beep boop\n' ); if ( err instanceof Error ) { // You choose what to do... throw err; }
var join = require( 'path' ).join;
var writeFile = require( '@stdlib/fs-write-file' );
var fpath = join( __dirname, 'examples', 'fixtures', 'file.txt' );
// Synchronously write data to a file:
var err = writeFile.sync( fpath, 'beep boop\n', 'utf8' );
// returns null
console.log( err instanceof Error );
// => false
// Asynchronously write data to a file:
writeFile( fpath, 'beep boop\n', onWrite );
function onWrite( error ) {
if ( error ) {
console.error( 'Error: %s', error.message );
}
console.log( 'Success!' );
}To use as a general utility, install the CLI package globally
npm install -g @stdlib/fs-write-file-cliUsage: write-file [options] <filepath>
Options:
-h, --help Print this message.
-V, --version Print the package version.
--enc, --encoding encoding Encoding. Default: 'utf8'.
--flag flag Flag. Default: 'r'.
--mode mode Mode. Default: 0o666.
- Relative output file paths are resolved relative to the current working directory.
- Errors are written to
stderr. - File contents should be provided over
stdinas part of a standard stream pipeline.
$ printf 'beep boop\n' | write-file ./examples/fixtures/file.txt@stdlib/fs-exists: test whether a path exists on the filesystem.@stdlib/fs-read-file: read the entire contents of a file.
This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.
For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.
See LICENSE.
Copyright © 2016-2023. The Stdlib Authors.
