prompt: print a horizontal line between prompt invocations

lib/prompt.py

@@ -165,6 +165,7 @@ class Settings:
 			self.cmd_start_time = int(argv[8]) if argv[8] else None
 			self.is_root = os.geteuid() == 0
 			self.is_daemon = os.geteuid() < 1000
+			self.horizontal_sep = "--no-horizontal-line" not in argv
 		except:
 			print("Usage: %s $COLUMNS $PWD last_refresh_time load_warn load_error space_warn space_error")
 			print("       e.g. %s 1 $COLUMNS $PWD 25 1.25 2.5 0.15 0.05")
@@ -712,11 +713,19 @@ class StatsPart(Part):
 					self.fragments.append(space_string(stor_free) %(stor_free_si[0], stor_free_si[1]))
 					self.fragments.append(style_reset())
 
+def make_horizontal_line(settings):
+	if settings.horizontal_sep:
+		return "─" * settings.term_width + "\n"
+
 if __name__ == "__main__":
 	settings = Settings(sys.argv)
 	sysload = Sysload()
 	overloaded = sysload.load1 >= settings.load_error
 	
+	hr = make_horizontal_line(settings)
+	if hr:
+		sys.stderr.write(hr)
+	
 	lp = LoginPart(settings, sysload)
 	pp = PathPart(settings, overloaded)
 	gp = "" if overloaded else GitPart()