ref: 1a324c3c7b0912a09c95ffd0d7c76c69b6e6af7c 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); }