[banner] display OS in init banner

src/lib/banner.c

@@ -17,6 +17,21 @@ init_banner_warnings(const notcurses* nc, fbuf* f, const char* clreol){
   return 0;
 }
 
+static inline const char*
+osname(void){
+#ifdef __MINGW64__
+  return "Windows";
+#elif defined(__APPLE__)
+  return "macOS";
+#elif defined(__gnu_hurd__)
+  return "GNU Hurd";
+#elif defined(BSD)
+  return "BSD";
+#else
+  return "Linux";
+#endif
+}
+
 // unless the suppress_banner flag was set, print some version information and
 // (if applicable) warnings to ttyfp. we are not yet on the alternate screen.
 int init_banner(const notcurses* nc, fbuf* f){
@@ -26,10 +41,11 @@ int init_banner(const notcurses* nc, fbuf* f){
   }
   if(!nc->suppress_banner){
     term_fg_palindex(nc, f, 50 % nc->tcache.caps.colors);
-    fbuf_printf(f, "%snotcurses %s on %s %s" NL,
+    fbuf_printf(f, "%snotcurses %s on %s %s (%s)" NL,
                 clreol, notcurses_version(),
                 nc->tcache.termname ? nc->tcache.termname : "?",
-                nc->tcache.termversion ? nc->tcache.termversion : "");
+                nc->tcache.termversion ? nc->tcache.termversion : "",
+                osname());
     term_fg_palindex(nc, f, nc->tcache.caps.colors <= 256 ?
                      14 % nc->tcache.caps.colors : 0x2080e0);
     if(nc->tcache.cellpixy && nc->tcache.cellpixx){