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About stdlib...

We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.

The library is fully decomposable, being architected in such a way that you can swap out and mix and match APIs and functionality to cater to your exact preferences and use cases.

When you use stdlib, you can be absolutely certain that you are using the most thorough, rigorous, well-written, studied, documented, tested, measured, and high-quality code out there.

To join us in bringing numerical computing to the web, get started by checking us out on GitHub, and please consider financially supporting stdlib. We greatly appreciate your continued support!

Open

NPM version Build Status Coverage Status

Open a file.

Usage

import open from 'https://cdn.jsdelivr.net/gh/stdlib-js/fs-open@esm/index.mjs';

You can also import the following named exports from the package:

import { sync } from 'https://cdn.jsdelivr.net/gh/stdlib-js/fs-open@esm/index.mjs';

open( path[, flags[, mode]], clbk )

Asynchronously opens a file.

var closeSync = require( 'https://cdn.jsdelivr.net/gh/stdlib-js/fs-close' ).sync;

open( __filename, onOpen );

function onOpen( error, fd ) {
    if ( error ) {
        console.error( error.message );
    } else {
        closeSync( fd );
    }
}

The function has the same default parameter values as fs.open().

open.sync( file[, flags[, mode]] )

Synchronously opens a file.

var closeSync = require( 'https://cdn.jsdelivr.net/gh/stdlib-js/fs-close' ).sync;

var fd = open.sync( __filename );
if ( fd instanceof Error ) {
    console.error( fd.message );
} else {
    closeSync( fd );
}

The function has the same default parameters as fs.openSync().

Notes

  • The difference between this API and fs.openSync() is that fs.openSync() will throw if an error is encountered (e.g., if given a non-existent path) and this API will return an error. Hence, the following anti-pattern

    var fs = require( 'fs' );

var fpath = '/path/to/file.js';
var fd;

// Check for existence to prevent an error being thrown...
if ( fs.existsSync( fpath ) ) {
    fd = fs.readFileSync( fpath );
}

    can be replaced by an approach which addresses existence via error handling.

    import open from 'https://cdn.jsdelivr.net/gh/stdlib-js/fs-open@esm/index.mjs';

var fpath = '/path/to/file.js';

// Explicitly handle the error...
var fd = open.sync( fpath );
if ( fd instanceof Error ) {
    // You choose what to do...
    console.error( fd.message );
}

Examples

<!DOCTYPE html>
<html lang="en">
<body>
<script type="module">

var join = require( 'path' ).join;
var closeSync = require( 'https://cdn.jsdelivr.net/gh/stdlib-js/fs-close' ).sync;
import open from 'https://cdn.jsdelivr.net/gh/stdlib-js/fs-open@esm/index.mjs';

/* Sync */

var fd = open.sync( join( __dirname, 'package.json' ), 'r+' );
// returns <number>

if ( fd instanceof Error ) {
    console.error( fd.message );
} else {
    closeSync( fd );
}

fd = open.sync( 'beepboop' );
// returns <Error>

/* Async */

open( join( __dirname, 'package.json' ), onOpen );
open( 'beepboop', onOpen );

function onOpen( error, fd ) {
    if ( error ) {
        if ( error.code === 'ENOENT' ) {
            console.error( 'File does not exist.' );
        } else {
            console.error( error.message );
        }
    } else {
        closeSync( fd );
    }
}

</script>
</body>
</html>

See Also

Notice

This package is part of stdlib, a standard library 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.

Community

Chat

License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.