What I'm trying to find:

• A function definition within a code file.

Information I have:

• Code file.
• The byte index of where the function definition starts in the code file and length in bytes.

How should I go about finding this function's line number in the file?

My current thoughts:

• Read code file as byte array
• Find function inside byte array by using start index and length for end.
• Convert this function from binary to text.
• Convert whole code file from binary to text.
• Number the lines in the text.
• Pattern match to find where the function is in the text and return line number.

I'm using Golang for the back-end service which I believe will execute this functionality. Though I also have a front-end in JavaScript which I can leverage to help if needed.