ref: a9105c84d1134fcf47d1fe05b7bdeb62192a3538
dir: /sys/src/ape/lib/ap/plan9/execvp.c/
#include <unistd.h>
#include <sys/limits.h>
#include <string.h>
extern char **environ;
/*
 * BUG: instead of looking at PATH env variable,
 * just try prepending /bin/ if name fails...
 */
int
execvp(const char *name, const char **argv)
{
	int n;
	char buf[PATH_MAX];
	if((n=execve(name, argv, environ)) < 0){
		strcpy(buf, "/bin/");
		strcpy(buf+5, name);
		n = execve(buf, argv, environ);
	}
	return n;
}