ref: 76b51dc816a4e6ad1d21b6b40b8ea32a57bd47a6 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); }