@stdlib/os-byte-order

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Byte Order

Platform byte order.

Installation

npm install @stdlib/os-byte-order

Alternatively,

• To load the package in a website via a script tag without installation and bundlers, use the ES Module available on the esm branch (see README).
• If you are using Deno, visit the deno branch (see README for usage intructions).
• For use in Observable, or in browser/node environments, use the Universal Module Definition (UMD) build available on the umd branch (see README).
• To use as a general utility for the command line, install the corresponding CLI package globally.

The branches.md file summarizes the available branches and displays a diagram illustrating their relationships.

To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.

Usage

var BYTE_ORDER = require( '@stdlib/os-byte-order' );

BYTE_ORDER

Platform byte order.

console.log( BYTE_ORDER );
// => <string>

Notes

• The following values are possible:

  • 'little-endian'
  • 'big-endian'
  • 'mixed-endian' (also known as "middle-endian")
  • 'unknown'

Examples

var BYTE_ORDER = require( '@stdlib/os-byte-order' );

if ( BYTE_ORDER === 'little-endian' ) {
    console.log( 'Least significant byte comes first...' );
} else if ( BYTE_ORDER === 'big-endian' ) {
    console.log( 'Most significant byte comes first...' );
} else {
    console.log( 'This is uncommon...' );
}

---

C APIs

Usage

#include "stdlib/os/byte_order.h"

STDLIB_OS_ORDER_LITTLE_ENDIAN

Macro for an arbitrary constant indicating little-endian order.

#if defined(STDLIB_OS_BYTE_ORDER) && STDLIB_OS_BYTE_ORDER == STDLIB_OS_ORDER_LITTLE_ENDIAN

// Do something for little-endian...

#endif

If compiled on an unrecognized/unsupported platform, the macro is not defined.

STDLIB_OS_ORDER_BIG_ENDIAN

Macro for an arbitrary constant indicating big-endian order.

#if defined(STDLIB_OS_BYTE_ORDER) && STDLIB_OS_BYTE_ORDER == STDLIB_OS_ORDER_BIG_ENDIAN

// Do something for big-endian...

#endif

If compiled on an unrecognized/unsupported platform, the macro is not defined.

STDLIB_OS_BYTE_ORDER

Macro which equals either STDLIB_OS_ORDER_LITTLE_ENDIAN or STDLIB_OS_ORDER_BIG_ENDIAN (or host defined) depending on the resolved platform byte order.

#if defined(STDLIB_OS_BYTE_ORDER)

#if STDLIB_OS_BYTE_ORDER == STDLIB_OS_ORDER_LITTLE_ENDIAN

// Do something for little-endian...

#elif STDLIB_OS_BYTE_ORDER == STDLIB_OS_ORDER_BIG_ENDIAN

// Do something for big-endian...

#endif

#endif

If compiled on an unrecognized/unsupported platform, the macro is not defined.

Examples

#include "stdlib/os/byte_order.h"
#include <stdio.h>

int main( void ) {
#if defined(STDLIB_OS_BYTE_ORDER)
#if STDLIB_OS_BYTE_ORDER == STDLIB_OS_ORDER_LITTLE_ENDIAN
    printf( "Platform is little-endian...\n" );
#elif STDLIB_OS_BYTE_ORDER == STDLIB_OS_ORDER_BIG_ENDIAN
    printf( "Platform is big-endian...\n" );
#else
    printf( "Platform endianness is either mixed-endian or unknown...\n" )
#endif
#endif
}

---

CLI

Installation

To use as a general utility, install the CLI package globally

npm install -g @stdlib/os-byte-order-cli

Usage

Usage: byte-order [options]

Options:

  -h,    --help                Print this message.
  -V,    --version             Print the package version.

Examples

$ byte-order

---

See Also

• @stdlib/assert-is-big-endian: check if an environment is big endian.
• @stdlib/assert-is-little-endian: check if an environment is little endian.

---

Notice

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.

Community

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License

See LICENSE.

Copyright

Copyright 2016-2026. The Stdlib Authors.