Your program contains 3 files: info.h, info.c, main.c. You also added a correct makefile. if you did some changes on the file main.c only after the first execution of command (make). What is the output of executing the command (make) again goc-c main.c O gcc-c info.c gcc -c main.c gcc info.o main.o -o project gcc info.o main.o -o project O gcc-c mainc gcc info.o main.o -o project