Use subprocess instead of os.system

src/click/_termui_impl.py

@@ -12,6 +12,7 @@
 import typing as t
 from gettext import gettext as _
 from io import StringIO
+from shutil import which
 from types import TracebackType
 
 from ._compat import _default_text_stdout
@@ -377,16 +378,16 @@ 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)
-    if hasattr(os, "system") and os.system("(less) 2>/dev/null") == 0:
+        return _tempfilepager(generator, "more", color, pipe=True)
+    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(f'more "{filename}"') == 0:
+        if which("more") is not None:
             return _pipepager(generator, "more", color)
         return _nullpager(stdout, generator, color)
     finally:
@@ -444,9 +445,17 @@ 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."""
+    """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`.
+    """
+    import subprocess
     import tempfile
 
     fd, filename = tempfile.mkstemp()
@@ -458,7 +467,14 @@ def _tempfilepager(
     with open_stream(filename, "wb")[0] as f:
         f.write(text.encode(encoding))
     try:
-        os.system(f'{cmd} "{filename}"')
+        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
     finally:
         os.close(fd)
         os.unlink(filename)
@@ -497,7 +513,7 @@ def get_editor(self) -> str:
         if WIN:
             return "notepad"
         for editor in "sensible-editor", "vim", "nano":
-            if os.system(f"which {editor} >/dev/null 2>&1") == 0:
+            if which(editor) is not None:
                 return editor
         return "vi"
 
@@ -596,22 +612,33 @@ def _unquote_file(url: str) -> str:
             null.close()
     elif WIN:
         if locate:
-            url = _unquote_file(url.replace('"', ""))
-            args = f'explorer /select,"{url}"'
+            url = _unquote_file(url)
+            args = ["explorer", f"/select,{url}"]
         else:
-            url = url.replace('"', "")
-            wait_str = "/WAIT" if wait else ""
-            args = f'start {wait_str} "" "{url}"'
-        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 = os.path.dirname(_unquote_file(url).replace('"', ""))
-            args = f'cygstart "{url}"'
+            url = _unquote_file(url)
+            args = ["cygstart", os.path.dirname(url)]
         else:
-            url = url.replace('"', "")
-            wait_str = "-w" if wait else ""
-            args = f'cygstart {wait_str} "{url}"'
-        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:

tests/test_imports.py

@@ -47,6 +47,7 @@ def tracking_import(module, locals=None, globals=None, fromlist=None,
     "typing",
     "types",
     "gettext",
+    "shutil",
 }
 
 if WIN: