Maximum number of files that can be open and processes that can be spawned-CodePudding

When I was running a program that modifies files, and had loaded exactly 1000 files, the program aborted with the message:

Process launching failed: Too many open files

Where can I find the C constant to use in my code to figure out the maximum number of files that can be open and processes that can be spawned all at once?

CodePudding user response：

On POSIX-compatible systems, you can use the getrlimit function with the RLIMIT_NOFILE parameter.

#include <sys/resource.h>

rlim_t get_open_files_limit() {
    struct rlimit limit;
    getrlimit(RLIMIT_NOFILE, &limit);
    return limit.rlim_cur;
}

Some systems (Linux, BSD, maybe others?) define an RLIMIT_NPROC on top of this which can tell you the maximum number of processes that the user is allowed to create. See FreeBSD-specific documentation, Linux-specific documentation.