[dadie]

Probably off-topic: I may miss something but I have the feeling the shown C program should segfault a lot as the variable `fname` in `char* make_filename(const char*)` does not seem to be initialized.

[ab71e5]

Yeah it should be something like

    char fname[BUFSIZE];

Also better to pass that in as a variable I don't think you can return a char array allocated on the stack like that