ioctl_nsfs - ioctl() operations for Linux namespaces
#include <linux/nsfs.h> /* Definition of NS_* constants */
#include <sys/ioctl.h>
int ioctl(int fd, unsigned long op, ...);
fd does not refer to a /proc/pid/ns/*
file.
Linux.
ioctl(2), fstat(2), proc(5), namespaces(7)