ref: de7a6a9d492ddc55fe32bf9de0aad6d9e12e94e1 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); }