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javascriptnode.jstypescriptbuffer

Javascript - How to convert buffer to a string?


This is example of converting String to a Buffer and back to String:

let bufferOne = Buffer.from('This is a buffer example.');
console.log(bufferOne);

// Output: <Buffer 54 68 69 73 20 69 73 20 61 20 62 75 66 66 65 72 20 65 78 61 6d 70 6c 65 2e>

let json = JSON.stringify(bufferOne);
let bufferOriginal = Buffer.from(JSON.parse(json).data);
console.log(bufferOriginal.toString('utf8'));
// Output: This is a buffer example.

Now imagine someone just give you only this string as a starting point:
<Buffer 54 68 69 73 20 69 73 20 61 20 62 75 66 66 65 72 20 65 78 61 6d 70 6c 65 2e>
- how would you convert it to regular value of this 'buffer' string?

I tried with:

   let buffer = '<Buffer 54 68 69 73 20 69 73 20 61 20 62 75 66 66 65 72 20 65 78 61 6d 70 6c 65 2e>'
    json = JSON.stringify(buffer);
    console.log(json);

Gives output:

"<Buffer 54 68 69 73 20 69 73 20 61 20 62 75 66 66 65 72 20 65 78 61 6d 70 6c 65 2e>"

Solution

  • No native way for that, but I wrote a sample method for you:

    function bufferFromBufferString(bufferStr) {
        return Buffer.from(
            bufferStr
                .replace(/[<>]/g, '') // remove < > symbols from str
                .split(' ') // create an array splitting it by space
                .slice(1) // remove Buffer word from an array
                .reduce((acc, val) => 
                    acc.concat(parseInt(val, 16)), [])  // convert all strings of numbers to hex numbers
         )
    }
    

    result:

    const newBuffer = bufferFromBufferString('<Buffer 54 68 69 73 20 69 73 20 61 20 62 75 66 66 65 72 20 65 78 61 6d 70 6c 65 2e>')
    > newBuffer
    <Buffer 54 68 69 73 20 69 73 20 61 20 62 75 66 66 65 72 20 65 78 61 6d 70 6c 65 2e>
    > newBuffer.toString()
    'This is a buffer example.'