Improve login shell detection

- Use pwd module to get user's login shell
- Add assertions to shell startup test

Author: Yoshihiro Takahara

src/mcp_shell_server/shell_executor.py

@@ -1,5 +1,6 @@
 import asyncio
 import os
+import pwd
 import shlex
 import time
 from typing import IO, Any, Dict, List, Optional, Tuple, Union
@@ -379,8 +380,11 @@ def _preprocess_command(self, command: List[str]) -> List[str]:
         return preprocessed_command
 
     def _get_default_shell(self) -> str:
-        """Get the default shell from environment variables"""
-        return os.environ.get("SHELL", "/bin/sh")
+        """Get the login shell of the current user"""
+        try:
+            return pwd.getpwuid(os.getuid()).pw_shell
+        except (ImportError, KeyError):
+            return os.environ.get("SHELL", "/bin/sh")
 
     async def execute(
         self,

tests/test_server.py

@@ -332,7 +332,8 @@ async def test_shell_startup(monkeypatch, temp_test_dir):
         "shell_execute",
         {"command": ["ps", "-p", "$$", "-o", "command="], "directory": temp_test_dir},
     )
-    print("Shell process info:", result)  # Debug output
+    assert len(result) == 1
+    assert "sh" in result[0].text or "bash" in result[0].text or "zsh" in result[0].text
 
 
 @pytest.mark.asyncio
@@ -344,4 +345,3 @@ async def test_environment_variables(monkeypatch, temp_test_dir):
         {"command": ["env"], "directory": temp_test_dir},
     )
     assert len(result) == 1
-    print(result[0].text)  # 環境変数の内容を確認