ref: bb2357de0cf04c6d8f41e7f7f72f1c033181d4e7 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); }