What is the best way to search for files by name without winApi?

Question

QNX

The class has a method that creates a txt file named with the current date and time (for example: 2017-11-14-21-51-00). There will be a huge number of files.
It is necessary without using winapi, because. development under qnx, display the names of all files included in the range of entered dates.
P.S. I do not need to write code, I will be glad if someone tells me the solution to this problem in the form of an "idea".

Answer 1

man readdir
...
struct dirent *readdir(DIR *dirp);
int readdir_r(DIR *dirp, struct dirent *entry, struct dirent **result);
and further in all unixes.