API refactor

venv/lib/python3.12/site-packages/dotenv/cli.py

@@ -3,8 +3,10 @@ import os
 import shlex
 import sys
 from contextlib import contextmanager
-from subprocess import Popen
-from typing import Any, Dict, IO, Iterator, List
+from typing import Any, Dict, IO, Iterator, List, Optional
+
+if sys.platform == 'win32':
+    from subprocess import Popen
 
 try:
     import click
@@ -17,7 +19,7 @@ from .main import dotenv_values, set_key, unset_key
 from .version import __version__
 
 
-def enumerate_env():
+def enumerate_env() -> Optional[str]:
     """
     Return a path for the ${pwd}/.env file.
 
@@ -161,14 +163,13 @@ def run(ctx: click.Context, override: bool, commandline: List[str]) -> None:
     if not commandline:
         click.echo('No command given.')
         exit(1)
-    ret = run_command(commandline, dotenv_as_dict)
-    exit(ret)
+    run_command(commandline, dotenv_as_dict)
 
 
-def run_command(command: List[str], env: Dict[str, str]) -> int:
-    """Run command in sub process.
+def run_command(command: List[str], env: Dict[str, str]) -> None:
+    """Replace the current process with the specified command.
 
-    Runs the command in a sub process with the variables from `env`
+    Replaces the current process with the specified command and the variables from `env`
     added in the current environment variables.
 
     Parameters
@@ -180,8 +181,8 @@ def run_command(command: List[str], env: Dict[str, str]) -> int:
 
     Returns
     -------
-    int
-        The return code of the command
+    None
+        This function does not return any value. It replaces the current process with the new one.
 
     """
     # copy the current environment variables and add the vales from
@@ -189,11 +190,16 @@ def run_command(command: List[str], env: Dict[str, str]) -> int:
     cmd_env = os.environ.copy()
     cmd_env.update(env)
 
-    p = Popen(command,
-              universal_newlines=True,
-              bufsize=0,
-              shell=False,
-              env=cmd_env)
-    _, _ = p.communicate()
+    if sys.platform == 'win32':
+        # execvpe on Windows returns control immediately
+        # rather than once the command has finished.
+        p = Popen(command,
+                  universal_newlines=True,
+                  bufsize=0,
+                  shell=False,
+                  env=cmd_env)
+        _, _ = p.communicate()
 
-    return p.returncode
+        exit(p.returncode)
+    else:
+        os.execvpe(command[0], args=command, env=cmd_env)