From 3eca15d4e9f3423477ecc4da1d466de22b78c89f Mon Sep 17 00:00:00 2001
From: "John T. Wodder II" <git@varonathe.org>
Date: Sat, 22 Feb 2020 14:32:56 -0500
Subject: [PATCH 1/7] [#1470,#1476] Use subprocess instead of os.system

---
 click/_compat.py      | 13 ++++++++
 click/_termui_impl.py | 71 ++++++++++++++++++++++++++++++++++---------
 click/termui.py       |  5 +--
 tests/test_imports.py |  2 +-
 4 files changed, 73 insertions(+), 18 deletions(-)

diff --git a/click/_compat.py b/click/_compat.py
index 5b5c73dd6..79061c022 100644
--- a/click/_compat.py
+++ b/click/_compat.py
@@ -258,6 +258,17 @@ def filename_to_ui(value):
         if isinstance(value, bytes):
             value = value.decode(get_filesystem_encoding(), 'replace')
         return value
+
+    def which(cmd):
+        import subprocess
+        try:
+            path = subprocess.check_output(
+                ['which', cmd],
+                stderr=subprocess.STDOUT,
+            )
+        except subprocess.CalledProcessError:
+            return None
+        return path.strip()
 else:
     text_type = str
     raw_input = input
@@ -461,6 +472,8 @@ def filename_to_ui(value):
                 .decode('utf-8', 'replace')
         return value
 
+    from shutil import which
+
 
 def get_streerror(e, default=None):
     if hasattr(e, 'strerror'):
diff --git a/click/_termui_impl.py b/click/_termui_impl.py
index 62eb95d21..2087840f6 100644
--- a/click/_termui_impl.py
+++ b/click/_termui_impl.py
@@ -18,7 +18,7 @@
 import contextlib
 from ._compat import _default_text_stdout, range_type, isatty, \
      open_stream, strip_ansi, term_len, get_best_encoding, WIN, int_types, \
-     CYGWIN
+     CYGWIN, which
 from .utils import echo
 from .exceptions import ClickException
 
@@ -333,15 +333,15 @@ def pager(generator, color=None):
     if os.environ.get('TERM') in ('dumb', 'emacs'):
         return _nullpager(stdout, generator, color)
     if WIN or sys.platform.startswith('os2'):
-        return _tempfilepager(generator, 'more <', color)
-    if hasattr(os, 'system') and os.system('(less) 2>/dev/null') == 0:
+        return _pipetempfilepager(generator, 'more', color)
+    if which('less') is not None:
         return _pipepager(generator, 'less', color)
 
     import tempfile
     fd, filename = tempfile.mkstemp()
     os.close(fd)
     try:
-        if hasattr(os, 'system') and os.system('more "%s"' % filename) == 0:
+        if which('more') is not None:
             return _pipepager(generator, 'more', color)
         return _nullpager(stdout, generator, color)
     finally:
@@ -399,6 +399,31 @@ def _pipepager(generator, cmd, color):
 
 def _tempfilepager(generator, cmd, color):
     """Page through text by invoking a program on a temporary file."""
+    import subprocess
+    import tempfile
+    filename = tempfile.mktemp()
+    # TODO: This never terminates if the passed generator never terminates.
+    text = "".join(generator)
+    if not color:
+        text = strip_ansi(text)
+    encoding = get_best_encoding(sys.stdout)
+    with open_stream(filename, 'wb')[0] as f:
+        f.write(text.encode(encoding))
+    try:
+        subprocess.call([cmd, filename])
+    except OSError:
+        # Command not found
+        pass
+    finally:
+        os.unlink(filename)
+
+
+def _pipetempfilepager(generator, cmd, color):
+    """
+    Page through text by invoking a program with a temporary file redirected
+    as input.
+    """
+    import subprocess
     import tempfile
     filename = tempfile.mktemp()
     # TODO: This never terminates if the passed generator never terminates.
@@ -409,7 +434,11 @@ def _tempfilepager(generator, cmd, color):
     with open_stream(filename, 'wb')[0] as f:
         f.write(text.encode(encoding))
     try:
-        os.system(cmd + ' "' + filename + '"')
+        with open_stream(filename, 'rb')[0] as f:
+            subprocess.call([cmd], stdin=f)
+    except OSError:
+        # Command not found
+        pass
     finally:
         os.unlink(filename)
 
@@ -441,7 +470,7 @@ def get_editor(self):
         if WIN:
             return 'notepad'
         for editor in 'sensible-editor', 'vim', 'nano':
-            if os.system('which %s >/dev/null 2>&1' % editor) == 0:
+            if which(editor) is not None:
                 return editor
         return 'vi'
 
@@ -532,20 +561,32 @@ def _unquote_file(url):
     elif WIN:
         if locate:
             url = _unquote_file(url)
-            args = 'explorer /select,"%s"' % _unquote_file(
-                url.replace('"', ''))
+            args = ['explorer', '/select,%s' % _unquote_file(url)]
         else:
-            args = 'start %s "" "%s"' % (
-                wait and '/WAIT' or '', url.replace('"', ''))
-        return os.system(args)
+            args = ['start']
+            if wait:
+                args.append('/WAIT')
+            args.append('')
+            args.append(url)
+        try:
+            return subprocess.call(args)
+        except OSError:
+            # Command not found
+            return 127
     elif CYGWIN:
         if locate:
             url = _unquote_file(url)
-            args = 'cygstart "%s"' % (os.path.dirname(url).replace('"', ''))
+            args = ['cygstart', os.path.dirname(url)]
         else:
-            args = 'cygstart %s "%s"' % (
-                wait and '-w' or '', url.replace('"', ''))
-        return os.system(args)
+            args = ['cygstart']
+            if wait:
+                args.append('-w')
+            args.append(url)
+        try:
+            return subprocess.call(args)
+        except OSError:
+            # Command not found
+            return 127
 
     try:
         if locate:
diff --git a/click/termui.py b/click/termui.py
index 764132309..811fb8e90 100644
--- a/click/termui.py
+++ b/click/termui.py
@@ -390,10 +390,11 @@ def clear():
     if not isatty(sys.stdout):
         return
     # If we're on Windows and we don't have colorama available, then we
-    # clear the screen by shelling out.  Otherwise we can use an escape
+    # clear the screen by invoking `cls`.  Otherwise we can use an escape
     # sequence.
     if WIN:
-        os.system('cls')
+        import subprocess
+        subprocess.check_call(['cls'])
     else:
         sys.stdout.write('\033[2J\033[1;1H')
 
diff --git a/tests/test_imports.py b/tests/test_imports.py
index 8e9a97df6..560673aa7 100644
--- a/tests/test_imports.py
+++ b/tests/test_imports.py
@@ -32,7 +32,7 @@ def tracking_import(module, locals=None, globals=None, fromlist=None,
 ALLOWED_IMPORTS = set([
     'weakref', 'os', 'struct', 'collections', 'sys', 'contextlib',
     'functools', 'stat', 're', 'codecs', 'inspect', 'itertools', 'io',
-    'threading', 'colorama', 'errno', 'fcntl', 'datetime'
+    'threading', 'colorama', 'errno', 'fcntl', 'datetime', 'shutil'
 ])
 
 if WIN:

From 6c11177e3aa83009077b1b739f7321cf115e3cba Mon Sep 17 00:00:00 2001
From: Andreas Backx <andreas@backx.org>
Date: Sat, 26 Oct 2024 15:25:37 +0100
Subject: [PATCH 2/7] Merge _pipetempfilepager into _tempfilepager, fix double
 unquoting.

---
 src/click/_termui_impl.py | 44 +++++++++++++--------------------------
 1 file changed, 14 insertions(+), 30 deletions(-)

diff --git a/src/click/_termui_impl.py b/src/click/_termui_impl.py
index ff80ced24..c582b4802 100644
--- a/src/click/_termui_impl.py
+++ b/src/click/_termui_impl.py
@@ -378,7 +378,7 @@ def pager(generator: t.Iterable[str], color: t.Optional[bool] = None) -> None:
     if os.environ.get("TERM") in ("dumb", "emacs"):
         return _nullpager(stdout, generator, color)
     if WIN or sys.platform.startswith("os2"):
-        return _pipetempfilepager(generator, "more", color)
+        return _tempfilepager(generator, "more", color, pipe=True)
     if which("less") is not None:
         return _pipepager(generator, "less", color)
 
@@ -445,34 +445,15 @@ def _pipepager(generator: t.Iterable[str], cmd: str, color: t.Optional[bool]) ->
 
 
 def _tempfilepager(
-    generator: t.Iterable[str], cmd: str, color: t.Optional[bool]
+    generator: t.Iterable[str],
+    cmd: str,
+    color: t.Optional[bool],
+    pipe: bool = False,
 ) -> None:
-    """Page through text by invoking a program on a temporary file."""
-    import subprocess
-    import tempfile
+    """Page through text by invoking a program on a temporary file.
 
-    fd, filename = tempfile.mkstemp()
-    # TODO: This never terminates if the passed generator never terminates.
-    text = "".join(generator)
-    if not color:
-        text = strip_ansi(text)
-    encoding = get_best_encoding(sys.stdout)
-    with open_stream(filename, "wb")[0] as f:
-        f.write(text.encode(encoding))
-    try:
-        subprocess.call([cmd, filename])
-    except OSError:
-        # Command not found
-        pass
-    finally:
-        os.close(fd)
-        os.unlink(filename)
-
-
-def _pipetempfilepager(generator, cmd, color):
-    """
-    Page through text by invoking a program with a temporary file redirected
-    as input.
+    By default executes `cmd` as `cmd tmpfile`. If `pipe` is `True`, it will
+    instead pipe the text via stdin like `cat tmpfile | cmd`.
     """
     import subprocess
     import tempfile
@@ -486,8 +467,11 @@ def _pipetempfilepager(generator, cmd, color):
     with open_stream(filename, "wb")[0] as f:
         f.write(text.encode(encoding))
     try:
-        with open_stream(filename, "rb")[0] as f:
-            subprocess.call([cmd], stdin=f)
+        if pipe:
+            with open_stream(filename, "rb")[0] as f:
+                subprocess.call([cmd], stdin=f)
+        else:
+            subprocess.call([cmd, filename])
     except OSError:
         # Command not found
         pass
@@ -629,7 +613,7 @@ def _unquote_file(url: str) -> str:
     elif WIN:
         if locate:
             url = _unquote_file(url)
-            args = ["explorer", f"/select,{_unquote_file(url)}"]
+            args = ["explorer", f"/select,{url}"]
         else:
             args = ["start"]
             if wait:

From 976f3042e3a3a90512dc7a0bf1cbb63ed46a79d7 Mon Sep 17 00:00:00 2001
From: Andreas Backx <andreas@backx.org>
Date: Sat, 30 Nov 2024 18:20:46 +0000
Subject: [PATCH 3/7] Remove _tempfile_pager pipe command.

---
 src/click/_termui_impl.py | 31 ++++++++++++++-----------------
 tests/test_utils.py       |  9 +++++++--
 2 files changed, 21 insertions(+), 19 deletions(-)

diff --git a/src/click/_termui_impl.py b/src/click/_termui_impl.py
index c582b4802..a38c77179 100644
--- a/src/click/_termui_impl.py
+++ b/src/click/_termui_impl.py
@@ -378,7 +378,7 @@ def pager(generator: t.Iterable[str], color: t.Optional[bool] = None) -> None:
     if os.environ.get("TERM") in ("dumb", "emacs"):
         return _nullpager(stdout, generator, color)
     if WIN or sys.platform.startswith("os2"):
-        return _tempfilepager(generator, "more", color, pipe=True)
+        return _pipepager(generator, "more", color)
     if which("less") is not None:
         return _pipepager(generator, "less", color)
 
@@ -413,19 +413,25 @@ def _pipepager(generator: t.Iterable[str], cmd: str, color: t.Optional[bool]) ->
         elif "r" in less_flags or "R" in less_flags:
             color = True
 
-    c = subprocess.Popen(cmd, shell=True, stdin=subprocess.PIPE, env=env)
-    stdin = t.cast(t.BinaryIO, c.stdin)
-    encoding = get_best_encoding(stdin)
+    c = subprocess.Popen(
+        cmd,
+        shell=True,
+        stdin=subprocess.PIPE,
+        env=env,
+        errors="replace",
+        text=True,
+    )
+    assert c.stdin is not None
     try:
         for text in generator:
             if not color:
                 text = strip_ansi(text)
 
-            stdin.write(text.encode(encoding, "replace"))
+            c.stdin.write(text)
     except (OSError, KeyboardInterrupt):
         pass
     else:
-        stdin.close()
+        c.stdin.close()
 
     # Less doesn't respect ^C, but catches it for its own UI purposes (aborting
     # search or other commands inside less).
@@ -448,13 +454,8 @@ def _tempfilepager(
     generator: t.Iterable[str],
     cmd: str,
     color: t.Optional[bool],
-    pipe: bool = False,
 ) -> None:
-    """Page through text by invoking a program on a temporary file.
-
-    By default executes `cmd` as `cmd tmpfile`. If `pipe` is `True`, it will
-    instead pipe the text via stdin like `cat tmpfile | cmd`.
-    """
+    """Page through text by invoking a program on a temporary file."""
     import subprocess
     import tempfile
 
@@ -467,11 +468,7 @@ def _tempfilepager(
     with open_stream(filename, "wb")[0] as f:
         f.write(text.encode(encoding))
     try:
-        if pipe:
-            with open_stream(filename, "rb")[0] as f:
-                subprocess.call([cmd], stdin=f)
-        else:
-            subprocess.call([cmd, filename])
+        subprocess.call([cmd, filename])
     except OSError:
         # Command not found
         pass
diff --git a/tests/test_utils.py b/tests/test_utils.py
index a1ed559b2..110a9dced 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -179,7 +179,6 @@ def _test_gen_func():
     yield "abc"
 
 
-@pytest.mark.skipif(WIN, reason="Different behavior on windows.")
 @pytest.mark.parametrize("cat", ["cat", "cat ", "cat "])
 @pytest.mark.parametrize(
     "test",
@@ -195,7 +194,8 @@ def _test_gen_func():
     ],
 )
 def test_echo_via_pager(monkeypatch, capfd, cat, test):
-    monkeypatch.setitem(os.environ, "PAGER", cat)
+    if not WIN:
+        monkeypatch.setitem(os.environ, "PAGER", cat)
     monkeypatch.setattr(click._termui_impl, "isatty", lambda x: True)
 
     expected_output = test[0]
@@ -204,6 +204,11 @@ def test_echo_via_pager(monkeypatch, capfd, cat, test):
     click.echo_via_pager(test_input)
 
     out, err = capfd.readouterr()
+    if WIN:
+        # Windows character changes.
+        expected_output = expected_output.replace("\n", "\r\n")
+        # more adds this when paging
+        expected_output += "\r\n"
     assert out == expected_output
 
 

From 22fa2d3f44e6668499a077b7b71ac09c8ce6a0c4 Mon Sep 17 00:00:00 2001
From: Andreas Backx <andreas@backx.org>
Date: Sat, 30 Nov 2024 18:34:00 +0000
Subject: [PATCH 4/7] Undo test changes, use _tempfilepager for more on
 Windows.

---
 src/click/_termui_impl.py | 2 +-
 tests/test_utils.py       | 9 ++-------
 2 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/src/click/_termui_impl.py b/src/click/_termui_impl.py
index a38c77179..2485d8c84 100644
--- a/src/click/_termui_impl.py
+++ b/src/click/_termui_impl.py
@@ -378,7 +378,7 @@ def pager(generator: t.Iterable[str], color: t.Optional[bool] = None) -> None:
     if os.environ.get("TERM") in ("dumb", "emacs"):
         return _nullpager(stdout, generator, color)
     if WIN or sys.platform.startswith("os2"):
-        return _pipepager(generator, "more", color)
+        return _tempfilepager(generator, "more", color)
     if which("less") is not None:
         return _pipepager(generator, "less", color)
 
diff --git a/tests/test_utils.py b/tests/test_utils.py
index 110a9dced..a1ed559b2 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -179,6 +179,7 @@ def _test_gen_func():
     yield "abc"
 
 
+@pytest.mark.skipif(WIN, reason="Different behavior on windows.")
 @pytest.mark.parametrize("cat", ["cat", "cat ", "cat "])
 @pytest.mark.parametrize(
     "test",
@@ -194,8 +195,7 @@ def _test_gen_func():
     ],
 )
 def test_echo_via_pager(monkeypatch, capfd, cat, test):
-    if not WIN:
-        monkeypatch.setitem(os.environ, "PAGER", cat)
+    monkeypatch.setitem(os.environ, "PAGER", cat)
     monkeypatch.setattr(click._termui_impl, "isatty", lambda x: True)
 
     expected_output = test[0]
@@ -204,11 +204,6 @@ def test_echo_via_pager(monkeypatch, capfd, cat, test):
     click.echo_via_pager(test_input)
 
     out, err = capfd.readouterr()
-    if WIN:
-        # Windows character changes.
-        expected_output = expected_output.replace("\n", "\r\n")
-        # more adds this when paging
-        expected_output += "\r\n"
     assert out == expected_output
 
 

From adc0b2264a2db028e4bbd5948c31c9df16727b03 Mon Sep 17 00:00:00 2001
From: Andreas Backx <andreas@backx.org>
Date: Sat, 30 Nov 2024 19:05:25 +0000
Subject: [PATCH 5/7] Enabled Windows tests again, fixed \r\n suffix with more,
 and use which.

---
 examples/termui/termui.py |  3 +++
 src/click/_termui_impl.py | 50 +++++++++++++++++++++++++++++----------
 tests/test_utils.py       |  4 +++-
 3 files changed, 43 insertions(+), 14 deletions(-)

diff --git a/examples/termui/termui.py b/examples/termui/termui.py
index e72e65e5f..78d522f97 100644
--- a/examples/termui/termui.py
+++ b/examples/termui/termui.py
@@ -167,3 +167,6 @@ def menu():
                 click.echo("Invalid input")
         elif menu == "quit":
             return
+
+if __name__ == "__main__":
+    pager()
diff --git a/src/click/_termui_impl.py b/src/click/_termui_impl.py
index 2485d8c84..ad9f8f6c9 100644
--- a/src/click/_termui_impl.py
+++ b/src/click/_termui_impl.py
@@ -373,31 +373,42 @@ def pager(generator: t.Iterable[str], color: t.Optional[bool] = None) -> None:
     pager_cmd = (os.environ.get("PAGER", None) or "").strip()
     if pager_cmd:
         if WIN:
-            return _tempfilepager(generator, pager_cmd, color)
-        return _pipepager(generator, pager_cmd, color)
+            if _tempfilepager(generator, pager_cmd, color):
+                return
+        elif _pipepager(generator, pager_cmd, color):
+            return
     if os.environ.get("TERM") in ("dumb", "emacs"):
         return _nullpager(stdout, generator, color)
-    if WIN or sys.platform.startswith("os2"):
-        return _tempfilepager(generator, "more", color)
-    if which("less") is not None:
-        return _pipepager(generator, "less", color)
+    if (WIN or sys.platform.startswith("os2")) and _tempfilepager(
+        generator, "more", color
+    ):
+        return
+    if _pipepager(generator, "less", color):
+        return
 
     import tempfile
 
     fd, filename = tempfile.mkstemp()
     os.close(fd)
     try:
-        if which("more") is not None:
-            return _pipepager(generator, "more", color)
+        if _pipepager(generator, "more", color):
+            return
         return _nullpager(stdout, generator, color)
     finally:
         os.unlink(filename)
 
 
-def _pipepager(generator: t.Iterable[str], cmd: str, color: t.Optional[bool]) -> None:
+def _pipepager(generator: t.Iterable[str], cmd: str, color: t.Optional[bool]) -> bool:
     """Page through text by feeding it to another program.  Invoking a
     pager through this might support colors.
+
+    Returns True if the command was found, False otherwise and thus another
+    pager should be attempted.
     """
+    cmd_absolute = which(cmd)
+    if cmd_absolute is None:
+        return False
+
     import subprocess
 
     env = dict(os.environ)
@@ -414,7 +425,7 @@ def _pipepager(generator: t.Iterable[str], cmd: str, color: t.Optional[bool]) ->
             color = True
 
     c = subprocess.Popen(
-        cmd,
+        [cmd_absolute],
         shell=True,
         stdin=subprocess.PIPE,
         env=env,
@@ -449,13 +460,24 @@ def _pipepager(generator: t.Iterable[str], cmd: str, color: t.Optional[bool]) ->
         else:
             break
 
+    return True
+
 
 def _tempfilepager(
     generator: t.Iterable[str],
     cmd: str,
     color: t.Optional[bool],
-) -> None:
-    """Page through text by invoking a program on a temporary file."""
+) -> bool:
+    """Page through text by invoking a program on a temporary file.
+
+    Returns True if the command was found, False otherwise and thus another
+    pager should be attempted.
+    """
+    # Which is necessary for Windows, it is also recommended in the Popen docs.
+    cmd_absolute = which(cmd)
+    if cmd_absolute is None:
+        return False
+
     import subprocess
     import tempfile
 
@@ -468,7 +490,7 @@ def _tempfilepager(
     with open_stream(filename, "wb")[0] as f:
         f.write(text.encode(encoding))
     try:
-        subprocess.call([cmd, filename])
+        subprocess.call([cmd_absolute, filename])
     except OSError:
         # Command not found
         pass
@@ -476,6 +498,8 @@ def _tempfilepager(
         os.close(fd)
         os.unlink(filename)
 
+    return True
+
 
 def _nullpager(
     stream: t.TextIO, generator: t.Iterable[str], color: t.Optional[bool]
diff --git a/tests/test_utils.py b/tests/test_utils.py
index a1ed559b2..003315639 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -179,7 +179,6 @@ def _test_gen_func():
     yield "abc"
 
 
-@pytest.mark.skipif(WIN, reason="Different behavior on windows.")
 @pytest.mark.parametrize("cat", ["cat", "cat ", "cat "])
 @pytest.mark.parametrize(
     "test",
@@ -204,6 +203,9 @@ def test_echo_via_pager(monkeypatch, capfd, cat, test):
     click.echo_via_pager(test_input)
 
     out, err = capfd.readouterr()
+    if WIN:
+        # Windows character changes.
+        expected_output = expected_output.replace("\n", "\r\n")
     assert out == expected_output
 
 

From 0663bca622022bcfb217c5486962b672f4e2e971 Mon Sep 17 00:00:00 2001
From: Andreas Backx <andreas@backx.org>
Date: Sat, 30 Nov 2024 19:20:03 +0000
Subject: [PATCH 6/7] Remove Windows test change.

---
 tests/test_utils.py | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/tests/test_utils.py b/tests/test_utils.py
index 003315639..d80aee716 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -203,9 +203,6 @@ def test_echo_via_pager(monkeypatch, capfd, cat, test):
     click.echo_via_pager(test_input)
 
     out, err = capfd.readouterr()
-    if WIN:
-        # Windows character changes.
-        expected_output = expected_output.replace("\n", "\r\n")
     assert out == expected_output
 
 

From 29dc0430f1e5f68b0806c2832446314525e49474 Mon Sep 17 00:00:00 2001
From: Andreas Backx <andreas@backx.org>
Date: Sat, 30 Nov 2024 19:22:35 +0000
Subject: [PATCH 7/7] Remove added testing in example.

---
 examples/termui/termui.py | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/examples/termui/termui.py b/examples/termui/termui.py
index 78d522f97..e72e65e5f 100644
--- a/examples/termui/termui.py
+++ b/examples/termui/termui.py
@@ -167,6 +167,3 @@ def menu():
                 click.echo("Invalid input")
         elif menu == "quit":
             return
-
-if __name__ == "__main__":
-    pager()