1"""Basic tests for os.popen()
2
3  Particularly useful for platforms that fake popen.
4"""
5
6import unittest
7from test import support
8import os, sys
9
10if not hasattr(os, 'popen'):
11    raise unittest.SkipTest("need os.popen()")
12
13# Test that command-lines get down as we expect.
14# To do this we execute:
15#    python -c "import sys;print(sys.argv)" {rest_of_commandline}
16# This results in Python being spawned and printing the sys.argv list.
17# We can then eval() the result of this, and see what each argv was.
18python = sys.executable
19if ' ' in python:
20    python = '"' + python + '"'     # quote embedded space for cmdline
21
22@support.requires_subprocess()
23class PopenTest(unittest.TestCase):
24
25    def _do_test_commandline(self, cmdline, expected):
26        cmd = '%s -c "import sys; print(sys.argv)" %s'
27        cmd = cmd % (python, cmdline)
28        with os.popen(cmd) as p:
29            data = p.read()
30        got = eval(data)[1:] # strip off argv[0]
31        self.assertEqual(got, expected)
32
33    def test_popen(self):
34        self.assertRaises(TypeError, os.popen)
35        self._do_test_commandline(
36            "foo bar",
37            ["foo", "bar"]
38        )
39        self._do_test_commandline(
40            'foo "spam and eggs" "silly walk"',
41            ["foo", "spam and eggs", "silly walk"]
42        )
43        self._do_test_commandline(
44            'foo "a \\"quoted\\" arg" bar',
45            ["foo", 'a "quoted" arg', "bar"]
46        )
47        support.reap_children()
48
49    def test_return_code(self):
50        self.assertEqual(os.popen("exit 0").close(), None)
51        status = os.popen("exit 42").close()
52        if os.name == 'nt':
53            self.assertEqual(status, 42)
54        else:
55            self.assertEqual(os.waitstatus_to_exitcode(status), 42)
56
57    def test_contextmanager(self):
58        with os.popen("echo hello") as f:
59            self.assertEqual(f.read(), "hello\n")
60
61    def test_iterating(self):
62        with os.popen("echo hello") as f:
63            self.assertEqual(list(f), ["hello\n"])
64
65    def test_keywords(self):
66        with os.popen(cmd="exit 0", mode="w", buffering=-1):
67            pass
68
69if __name__ == "__main__":
70    unittest.main()
71