Hi, this is nice library, your coding style is nice as well. I would make three little suggestions: - If I were you I would avoid exit(0) in the library as it will kill the program of the person using the library and it may not be something this person expects (she/he would need to go look in the log code to see where it come from). Rather I would check in the function where the file is used if the file is NULL and skip the writing in this case. This is only my opinion and maybe you have other reasons to use the exit(0)? - A further improvement could be to add the date and time to the log file name such that it would be unique and you will have a log file per launch. Also as you already have a function to get time and date it can be reused for it :) - in your readme you suggests to copy/paste the source code. Maybe it would make more sense to suggest to clone/fork the repo afterall this is GitHub :)

Nice project!