获取打开文件限制

Question

Is it possible to portably access the maximum number of files that can be simultaneously open within the current process, in C++ (eg the result of ulimit -n on unix systems)? I'm writing an application in C++ that potentially requires hundreds of open files, often more than the systems default maximum. Going over the maximum open file limit generally causes difficult to diagnose crashes, especially as most users are not aware of the limit. If I knew the limit at startup, I could potentially warn the user of potential issues, or give a better error message when things go wrong.

Answer 1

In POSIX-compatible systems (which I think includes Windows):

#include <sys/resource.h>

struct rlimit lim;
getrlimit(RLIMIT_NOFILE, &lim);
rlim_t max_files = lim.rlim_cur;