node-bitstring

BitString

a very simple bit operation module, this module is base created for dns header decode/encode.

npm install node-bitstring

Example

let BitString = require("node-bitstring");
 
// let bitOpt = new BitString(Buffer.alloc(2)); create a bit string with 32 bits
 
let bitOpt = new BitString(32);
//BitString {buffer: <Buffer 00 00 00 00>,binaryString: '00000000000000000000000000000000' }
//create a bit string with 32 bits
//should be a number which can divide by 8
//if not it will auto fill
 
bitOpt.set(0, 111111); //"11111100000000000000000000000000"
bitOpt.set(0, 000111); //"11000000000000000000000000000000"
bitOpt.set(0, "000111"); //"00011100000000000000000000000000"
// The number will conversion to the string if the number start will 0 it will be ignored
bitOpt.get(0, 10); //"0001110000"
bitOpt.get(0, 100); //"00011100000000000000000000000000"; if length out-of-bounds, the excess part will be ignored;
bitOpt.get(32, 100); //false; if index out-of-bounds, the excess part will be ignored;
 
bitOpt.buffer; // <Buffer 1c 00 00 00>
bitOpt.binaryString; // "00011100000000000000000000000000"

Instance Methods

BitString(data) : data Can be either a number or buffer; BitString#get(index,length): Returns a binary string; BitString#set(index,value): Set the value of the bits. index start position value should be number string "0" will be set to 0, other is 1. if value out-of-bounds, the excess part will be ignored;

BitString#bufferToBinaryString(buf) : Returns a binary string;

bitOpt.bufferToBinaryString(Buffer.alloc(4, "AABBCCDD", "hex")); //"10101010101110111100110011011101"

BitString#binaryStringToHexString(binaryString) : Returns a Hex string;

bitOpt#binaryStringToHexString("10101010101110111100110011011101") // "AABBCCDD"

Properties

BitString#buffer: The contents of the BitString.

BitString#binaryString: The contents of the BitString.

License

MIT