Set argv global variables from Python like tclsh would

EP-85

pysrc/tohil/__init__.py

@@ -304,9 +304,20 @@ def _init_tcl_env():
         }
         return [list 0 ""]
     }
+
+    # Clear in case we're being reloaded
+    unset -nocomplain ::argc ::argv ::argv0
     """
 
     _tohil.eval(tcl_init)
+    if _sys.argv:
+        # Set up argv globals as if we were tclsh
+        argv0 = _sys.argv[0]
+        argv = _sys.argv[1:]
+        argc = len(argv)
+        _tohil.call("set", "::argv0", argv0)
+        _tohil.call("set", "::argv", argv)
+        _tohil.call("set", "::argc", argc)
 
 _init_tcl_env()
 

tests/test_arg_globals.py

@@ -0,0 +1,28 @@
+import importlib
+import sys
+import unittest
+
+import tohil
+
+
+class TestArgGlobals(unittest.TestCase):
+    def test_empty_argv(self):
+        sys.argv = []
+        importlib.reload(tohil)
+        self.assertEqual(tohil.call("info", "exists", "::argv"), 0)
+        self.assertEqual(tohil.call("info", "exists", "::argv0"), 0)
+        self.assertEqual(tohil.call("info", "exists", "::argc"), 0)
+
+    def test_argv_blank(self):
+        sys.argv = [""]
+        importlib.reload(tohil)
+        self.assertEqual(tohil.call("set", "::argv", to=list), [])
+        self.assertEqual(tohil.call("set", "::argv0"), "")
+        self.assertEqual(tohil.call("set", "::argc"), 0)
+
+    def test_argv_multiple(self):
+        sys.argv = ["script.py", "arg1", "arg2"]
+        importlib.reload(tohil)
+        self.assertEqual(tohil.call("set", "::argv", to=list), sys.argv[1:])
+        self.assertEqual(tohil.call("set", "::argv0"), "script.py")
+        self.assertEqual(tohil.call("set", "::argc"), 2)