OrionLibC

#include <sys/syscall.h>
#include <errno.h>

/* Duplicate an open file descriptor */
int
dup(int oldfd)
{
	int ret;
	asm volatile("int $0x80" : "=a" (ret) : "0" (SYSCALL_DUP),
	             "c" (1), "S" (&oldfd));
	if (ret >= 0)
		return ret;
	errno = -ret;
	return -1;
}

/* Duplicate an open file descriptor to a specified file descriptor */
int
dup2(int oldfd, int newfd)
{
	int ret;
	asm volatile("int $0x80" : "=a" (ret) : "0" (SYSCALL_DUP2),
	             "c" (2), "S" (&oldfd));
	if (ret >= 0)
		return ret;
	errno = -ret;
	return -1;
}