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Description

This is an implementation of Python Struct to Javascript.

The idea is to make an easy interface like python struct in javascript to parse strings as C Types.

What is done

• Full unpack support. I implemented all types unpack from python struct
• Big Endian and Little endian Support. You can choose the endianess like you do in python struct.
• Make use of Typed Arrays, Array Buffer and DataView from HTML5 Spec

TODO

• Packing functions.

How to use it

In python, you use something like that for an int 1234:

import struct
data = '\xd2\x04\x00\x00'
struct.unpack("I", data)    #   This will return (1234,)

So in struct.js you will do basicly the same:

var data = '\xd2\x04\x00\x00';
struct.unpack("I", data);   //   This will return [1234]

It works also for multiple packed data, in python:

import struct
data = '\xe0#\x00\x00\x00\x00(Aa'
struct.unpack("Ifc", data)  #   This will return (9184, 10.5, 'a')

In struct.js:

var data = '\xe0#\x00\x00\x00\x00(Aa';
struct.unpack("Ifc", data); //  This will return [9184, 10.5, "a"]

The function syntax:

struct.unpack(fmt, string)

Arguments: fmt a string containing the types and endianess:

First Character is endianess (Optional)

• @ Little Endian
• = Little Endian
• < Little Endian
• > Big Endian
• ! Big Endian

First and/or other characters as the format:

• Format - C Type - Size - Description
• x Pad Byte - 1 - This just skips one byte at the data
• c char - 1 - String of Length 1
• b signed char - 1 - Integer
• B unsigned char - 1 - Integer
• ? boolean - 1 - Boolean
• h short int - 2 - Int
• H unsigned short - 2 - Integer
• i int - 4 - Integer
• I unsigned int - 4 - Integer
• l long integer - 4 - Integer
• L unsigned long - 4 - Integer
• q long long - 8 - Integer
• Q unsigned long long - 8 - Integer
• f float - 4 - Float
• d double - 8 - Double
• s char[] - ? - String
• p char[] - ? - String
• P void * - 4 - Integer

Returns : array with the elements