fix(agent): preserve full command output in temp logs

Return only a 10KB preview to the agent so large command results do not overwhelm conversations while keeping the full output available for follow-up reads. Add pytest to the project dependencies to make the regression tests runnable in the project venv.

app/agent/tools/impl/execute_command.py

@@ -5,7 +5,8 @@ import os
 import signal
 import subprocess
 from dataclasses import dataclass, field
-from typing import Optional, Type
+from tempfile import NamedTemporaryFile
+from typing import Optional, TextIO, Type
 
 from pydantic import BaseModel, Field
 
@@ -15,7 +16,7 @@ from app.log import logger
 
 DEFAULT_TIMEOUT_SECONDS = 60
 MAX_TIMEOUT_SECONDS = 300
-MAX_OUTPUT_CHARS = 6000
+MAX_OUTPUT_PREVIEW_BYTES = 10 * 1024
 READ_CHUNK_SIZE = 4096
 KILL_GRACE_SECONDS = 3
 COMMAND_CONCURRENCY_LIMIT = 2
@@ -25,40 +26,93 @@ _command_semaphore = asyncio.Semaphore(COMMAND_CONCURRENCY_LIMIT)
 
 @dataclass
 class _CommandOutput:
-    """保存受限命令输出，避免大输出一次性进入内存。"""
+    """保存前 10KB 预览，并在超限时将完整输出写入临时文件。"""
 
-    limit: int
+    preview_limit_bytes: int
-    stdout_chunks: list[str] = field(default_factory=list)
+    preview_entries: list[tuple[str, str]] = field(default_factory=list)
-    stderr_chunks: list[str] = field(default_factory=list)
+    captured_bytes: int = 0
-    captured_chars: int = 0
+    preview_truncated: bool = False
-    truncated: bool = False
+    temp_file_path: Optional[str] = None
+    temp_file_handle: Optional[TextIO] = None
+    last_written_stream: Optional[str] = None
+
+    @staticmethod
+    def _clip_text_to_bytes(text: str, byte_limit: int) -> str:
+        if byte_limit <= 0:
+            return ""
+        return text.encode("utf-8")[:byte_limit].decode("utf-8", errors="ignore")
+
+    def _write_chunk(self, stream_name: str, text: str) -> None:
+        if not self.temp_file_handle or not text:
+            return
+
+        if self.last_written_stream != stream_name:
+            if self.temp_file_handle.tell() > 0:
+                self.temp_file_handle.write("\n")
+            title = "标准输出" if stream_name == "stdout" else "错误输出"
+            self.temp_file_handle.write(f"[{title}]\n")
+            self.last_written_stream = stream_name
+
+        self.temp_file_handle.write(text)
+
+    def _ensure_temp_file(self) -> None:
+        if self.temp_file_handle:
+            return
+
+        temp_file = NamedTemporaryFile(
+            mode="w",
+            encoding="utf-8",
+            suffix=".log",
+            prefix="moviepilot-command-",
+            delete=False,
+        )
+        self.temp_file_path = temp_file.name
+        self.temp_file_handle = temp_file
+        for stream_name, chunk in self.preview_entries:
+            self._write_chunk(stream_name, chunk)
+
+    def close(self) -> None:
+        if not self.temp_file_handle:
+            return
+        self.temp_file_handle.flush()
+        self.temp_file_handle.close()
+        self.temp_file_handle = None
 
     def append(self, stream_name: str, text: str) -> None:
         if not text:
             return
 
-        remaining = self.limit - self.captured_chars
+        if self.temp_file_handle:
-        if remaining <= 0:
+            self._write_chunk(stream_name, text)
-            self.truncated = True
             return
 
-        captured = text[:remaining]
+        chunk_bytes = len(text.encode("utf-8"))
-        if stream_name == "stdout":
+        remaining = self.preview_limit_bytes - self.captured_bytes
-            self.stdout_chunks.append(captured)
+        if chunk_bytes <= remaining:
-        else:
+            self.preview_entries.append((stream_name, text))
-            self.stderr_chunks.append(captured)
+            self.captured_bytes += chunk_bytes
+            return
 
-        self.captured_chars += len(captured)
+        self.preview_truncated = True
-        if len(text) > remaining:
+        self._ensure_temp_file()
-            self.truncated = True
+        self._write_chunk(stream_name, text)
+
+        preview = self._clip_text_to_bytes(text, remaining)
+        if preview:
+            self.preview_entries.append((stream_name, preview))
+            self.captured_bytes += len(preview.encode("utf-8"))
 
     @property
     def stdout(self) -> str:
-        return "".join(self.stdout_chunks).strip()
+        return "".join(
+            text for stream_name, text in self.preview_entries if stream_name == "stdout"
+        ).strip()
 
     @property
     def stderr(self) -> str:
-        return "".join(self.stderr_chunks).strip()
+        return "".join(
+            text for stream_name, text in self.preview_entries if stream_name == "stderr"
+        ).strip()
 
 
 class ExecuteCommandInput(BaseModel):
@@ -78,7 +132,7 @@ class ExecuteCommandTool(MoviePilotTool):
     description: str = (
         "Safely execute shell commands on the server. Useful for system "
         "maintenance, checking status, or running custom scripts. Includes "
-        "timeout, concurrency, and hard output limits."
+        "timeout, concurrency, and output preview limits."
     )
     args_schema: Type[BaseModel] = ExecuteCommandInput
     require_admin: bool = True
@@ -107,7 +161,7 @@ class ExecuteCommandTool(MoviePilotTool):
 
     @staticmethod
     def _subprocess_kwargs() -> dict:
-        """为子进程创建独立进程组，便于超时或输出过大时清理整棵子进程。"""
+        """为子进程创建独立进程组，便于超时场景清理整棵子进程。"""
         kwargs = {
             "stdin": subprocess.DEVNULL,
             "stdout": asyncio.subprocess.PIPE,
@@ -124,23 +178,14 @@ class ExecuteCommandTool(MoviePilotTool):
         stream: asyncio.StreamReader,
         stream_name: str,
         output: _CommandOutput,
-        limit_reached: asyncio.Event,
     ) -> None:
-        """按块读取输出，达到上限后通知主流程终止命令。"""
+        """按块读取输出，始终只把前 10KB 保留在返回结果中。"""
         while True:
             chunk = await stream.read(READ_CHUNK_SIZE)
             if not chunk:
                 break
 
-            if output.truncated:
-                limit_reached.set()
-                continue
-
             output.append(stream_name, chunk.decode("utf-8", errors="replace"))
-            if output.truncated:
-                limit_reached.set()
-                # 达到上限后继续排空管道但不再保存内容，避免子进程因 pipe 反压卡住。
-                continue
 
     @staticmethod
     def _terminate_process(process: asyncio.subprocess.Process, sig: int):
@@ -205,27 +250,33 @@ class ExecuteCommandTool(MoviePilotTool):
         output: _CommandOutput,
         timeout: int,
         timed_out: bool,
-        output_limited: bool,
         timeout_note: Optional[str],
     ) -> str:
         if timed_out:
             result = f"命令执行超时 (限制: {timeout}秒，已终止进程)"
-        elif output_limited:
-            result = (
-                f"命令输出超过限制 (限制: {MAX_OUTPUT_CHARS}字符，"
-                f"已截断并终止进程，退出码: {exit_code})"
-            )
         else:
             result = f"命令执行完成 (退出码: {exit_code})"
 
         if timeout_note:
             result += f"\n\n提示:\n{timeout_note}"
+        if output.temp_file_path:
+            file_note = (
+                "截至命令终止前的完整输出"
+                if timed_out
+                else "完整输出"
+            )
+            result += (
+                "\n\n提示:\n"
+                f"命令输出超过 10KB，仅返回前 {MAX_OUTPUT_PREVIEW_BYTES} 字节内容。\n"
+                f"{file_note}已写入临时文件: {output.temp_file_path}\n"
+                "如需完整内容，请继续读取该文件。"
+            )
         if output.stdout:
             result += f"\n\n标准输出:\n{output.stdout}"
         if output.stderr:
             result += f"\n\n错误输出:\n{output.stderr}"
-        if output.truncated:
+        if output.preview_truncated:
-            result += "\n\n...(输出内容过长，已截断)"
+            result += "\n\n...(仅展示前 10KB 内容)"
         if not output.stdout and not output.stderr:
             result += "\n\n(无输出内容)"
         return result
@@ -252,51 +303,40 @@ class ExecuteCommandTool(MoviePilotTool):
 
         try:
             async with _command_semaphore:
-                # 命令输出可能非常大，必须边读边截断，不能使用 communicate() 一次性收集。
+                # 命令输出可能非常大，必须边读边落盘，不能使用 communicate() 一次性收集。
                 process = await asyncio.create_subprocess_shell(
                     command, **self._subprocess_kwargs()
                 )
-                output = _CommandOutput(limit=MAX_OUTPUT_CHARS)
+                output = _CommandOutput(preview_limit_bytes=MAX_OUTPUT_PREVIEW_BYTES)
-                limit_reached = asyncio.Event()
                 wait_task = asyncio.create_task(process.wait())
-                limit_task = asyncio.create_task(limit_reached.wait())
                 reader_tasks = [
                     asyncio.create_task(
-                        self._read_stream(
+                        self._read_stream(process.stdout, "stdout", output)
-                            process.stdout, "stdout", output, limit_reached
-                        )
                     ),
                     asyncio.create_task(
-                        self._read_stream(
+                        self._read_stream(process.stderr, "stderr", output)
-                            process.stderr, "stderr", output, limit_reached
-                        )
                     ),
                 ]
 
                 timed_out = False
-                output_limited = False
+                try:
-                done, _ = await asyncio.wait(
+                    await asyncio.wait_for(
-                    {wait_task, limit_task},
+                        asyncio.shield(wait_task), timeout=normalized_timeout
-                    timeout=normalized_timeout,
+                    )
-                    return_when=asyncio.FIRST_COMPLETED,
+                except asyncio.TimeoutError:
-                )
+                    timed_out = True
-
-                if wait_task not in done:
-                    if limit_task in done:
-                        output_limited = True
-                    else:
-                        timed_out = True
                     await self._cleanup_process(process, wait_task)
 
-                limit_task.cancel()
+                try:
-                await self._finish_reader_tasks(reader_tasks)
+                    await self._finish_reader_tasks(reader_tasks)
+                finally:
+                    output.close()
 
                 return self._format_result(
                     exit_code=process.returncode,
                     output=output,
                     timeout=normalized_timeout,
                     timed_out=timed_out,
-                    output_limited=output_limited,
                     timeout_note=timeout_note,
                 )
 

requirements.in

@@ -89,3 +89,4 @@ openai~=2.33.0
 google-genai~=1.74.0
 ddgs~=9.10.0
 websocket-client~=1.8.0
+pytest~=8.4.0

tests/test_execute_command_tool.py

@@ -1,5 +1,6 @@
 import asyncio
 import os
+import re
 import shlex
 import subprocess
 import sys
@@ -8,7 +9,7 @@ import unittest
 
 from app.agent.tools.impl.execute_command import (
     ExecuteCommandTool,
-    MAX_OUTPUT_CHARS,
+    MAX_OUTPUT_PREVIEW_BYTES,
 )
 
 
@@ -21,6 +22,11 @@ def _python_command(code: str) -> str:
 
 
 class TestExecuteCommandTool(unittest.TestCase):
+    def _temp_file_path_from_result(self, result: str) -> str:
+        match = re.search(r"临时文件: (.+)", result)
+        self.assertIsNotNone(match)
+        return match.group(1).strip()
+
     def _run_command(self, command: str, timeout: int = 60) -> str:
         tool = ExecuteCommandTool(session_id="session-1", user_id="10001")
         return asyncio.run(tool.run(command=command, timeout=timeout))
@@ -31,9 +37,19 @@ class TestExecuteCommandTool(unittest.TestCase):
         )
 
         result = self._run_command(command)
+        temp_file_path = self._temp_file_path_from_result(result)
 
-        self.assertIn("输出内容过长，已截断", result)
+        self.addCleanup(lambda: os.path.exists(temp_file_path) and os.unlink(temp_file_path))
-        self.assertLess(len(result), MAX_OUTPUT_CHARS + 500)
+        self.assertIn("命令输出超过 10KB", result)
+        self.assertIn("仅展示前 10KB 内容", result)
+        self.assertIn("如需完整内容，请继续读取该文件", result)
+        self.assertLess(len(result), MAX_OUTPUT_PREVIEW_BYTES + 600)
+
+        with open(temp_file_path, encoding="utf-8") as file_handle:
+            file_content = file_handle.read()
+
+        self.assertIn("[标准输出]", file_content)
+        self.assertGreater(len(file_content), 100000)
 
     def test_timeout_returns_partial_output_promptly(self):
         command = _python_command(
@@ -48,6 +64,24 @@ class TestExecuteCommandTool(unittest.TestCase):
         self.assertIn("命令执行超时", result)
         self.assertIn("started", result)
 
+    def test_timeout_with_large_output_writes_partial_full_log_to_temp_file(self):
+        command = _python_command(
+            "import sys, time; sys.stdout.write('x' * 20000); sys.stdout.flush(); time.sleep(5)"
+        )
+
+        result = self._run_command(command, timeout=1)
+        temp_file_path = self._temp_file_path_from_result(result)
+
+        self.addCleanup(lambda: os.path.exists(temp_file_path) and os.unlink(temp_file_path))
+        self.assertIn("命令执行超时", result)
+        self.assertIn("截至命令终止前的完整输出已写入临时文件", result)
+
+        with open(temp_file_path, encoding="utf-8") as file_handle:
+            file_content = file_handle.read()
+
+        self.assertIn("[标准输出]", file_content)
+        self.assertGreaterEqual(file_content.count("x"), 20000)
+
     def test_timeout_is_capped(self):
         command = _python_command("print('ok')")