how to write a simple makefile for c

Question

I need to write a simple make file for my.c, and so after

make

then my program can be run by

./my

Answer 1

simple make file for your program is

build : 
        gcc /your_full_path_to_c_file/cJ.c my.c -lcrypto -o my -lm

just copy this in one file keep name of that file as makefile then run as make build