git: 9front

ref: 62c69b81c7249ee4e69c44c64391cdf9d1a7fc3e
dir: /sys/src/ape/lib/ap/plan9/dup.c/

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#include "lib.h"
#include <unistd.h>
#include <errno.h>

int
dup(int oldd)
{
	return fcntl(oldd, F_DUPFD, 0);
}

int
dup2(int oldd, int newd)
{
	int n;

	if(newd < 0 || newd >= OPEN_MAX){
		errno = EBADF;
		return -1;
	}
	if(oldd == newd && _fdinfo[newd].flags&FD_ISOPEN)
		return newd;
	close(newd);
	return fcntl(oldd, F_DUPFD, newd);
}