Shell Scripting
 

A shell script which takes an image as input and converts that into a vector of the same size.

You're looking for a rasterizer of some sort, see for example
http://potrace.sourceforge.net/samples.html

I need code for reference

Imagemagick will do that I think if this is what you want
https://www.vectorizer.io/
http://potrace.sourceforge.net/
https://inkscape.org/en/

Then write some.

I am using convert file.jpg file.svg
but getting invalid parameter error

https://www.imagemagick.org/discourse-server/search.php
https://imagemagick.org/script/command-line-options.php

So read the man page or the documentation. And you ALSO need to read the "Question Guidelines" and "How to ask a smart question" links in my posting signature, along with the LQ Rules.

We WILL NOT write your scripts or do your homework for you. YOU, personally, are expected to do some research on your own, and show your own efforts, before posting. You now have four threads open with nothing but a homework question, and no efforts shown.

the imagemagick convert will NOT make a svg
it will put a svg wrapper around a jpg but it will NOT be a vector image

have a look at using "Trace Bitmap"