How to obtain all Latex source used in compilation of a Latex file by pdflatex.exe if the latex source file has many \input command

Question

I have a Latex file a.tex and I have used \input command inside in many places to include other latex files. I am giving this file as input to PDFLatex.exe command to generate PDF. I want to obtain the entire latex source code which is used to generate the PDF. I can obtain this manually, but is there an automated way?