lookupvar
str = lookupvar(varname);
home = lookupvar("HOME");
val = lookupvar(var);
set_prompt_lit(lookupvar("PSlit"), 0, NULL);
el_source(el, lookupvar("EDITRC"));
home = lookupvar("HOME");
if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
lookupvar("NETBSD_SHELL"));
fmt = lookupvar("ToD_FORMAT");
tz = lookupvar("TZ");
char *lookupvar(const char *);