ref: 3a0d5f41a8253b4a3fbb6ae4b6ca77789fd6ae83 dir: /sys/src/ape/lib/ap/plan9/execl.c/
#include <unistd.h> extern char **environ; int execl(const char *name, const char *arg0, ...) { return execve(name, &arg0, environ); }