All implementations impose a limit on the number of files that a process can open simultaneously. This limit depends on various factors such as the process’ privileges, the number of open files that other processes currently use, and the system’s resources. The constant FOPEN_MAX which is defined in ( in C) is the minimum number of files that the implementation guarantees can be open simultaneously by a single process. A process may occasionally succeed in opening a higher number of files. However, the system can guarantee only up to FOPEN_MAX open files per process at any given time.