C programming in unix environment ?

I have a program, that saves files to the current directory the program is running, its a simple program , just to save first name and last names, I wanted to know if there is source code to allow the user to see all files on the directory and decide which one to load to use, hope I made myself clear enough, the user gets an option to load data from a file into memory to edit and i want to show the user all files that exist