ai-agent-book 精选快照（<2MB 代码与文档，来自 github.com/bojieli/ai-agent-book）

chapter5/coding-agent/tools/bash_tool.py

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+"""
+Bash tool - Command execution in persistent shell sessions
+"""
+
+import time
+import hashlib
+from typing import Dict, Any
+from .base import BaseTool
+
+
+class BashTool(BaseTool):
+    """Executes bash commands in persistent shell sessions"""
+    
+    @property
+    def name(self) -> str:
+        return "Bash"
+    
+    def _execute_impl(self, params: Dict[str, Any]) -> Dict[str, Any]:
+        """
+        Execute bash command in persistent shell
+        
+        - Commands execute in a persistent shell session
+        - Working directory changes persist across commands
+        - Environment variables persist
+        - Supports background execution with run_in_background parameter
+        - Output truncated if exceeds 30000 characters
+        """
+        command = params["command"]
+        timeout_ms = params.get("timeout")
+        # None/<=0: treat like omit. Exact 0 used to become timeout=0s and drop all output.
+        if timeout_ms is None or timeout_ms <= 0:
+            timeout_ms = 120000
+        timeout = timeout_ms / 1000  # Convert ms to seconds
+        run_in_background = params.get("run_in_background", False)
+        
+        # Get or create shell session
+        shell_id = self.state.default_shell_id
+        if shell_id not in self.state.shell_sessions:
+            from .shell_session import ShellSession
+            self.state.shell_sessions[shell_id] = ShellSession(
+                session_id=shell_id,
+                current_directory=self.state.current_directory
+            )
+        
+        session = self.state.shell_sessions[shell_id]
+        
+        if run_in_background:
+            # Start a separate native-shell process. ShellSession handles the
+            # platform-specific invocation and log location.
+            bg_id = f"bg_{int(time.time())}_{hashlib.md5(command.encode()).hexdigest()[:8]}"
+            pid = session.start_background(command, bg_id)
+            
+            return {
+                "output": f"Background job started with ID: {bg_id}\nPID: {pid}",
+                "exit_code": 0,
+                "shell_id": shell_id,
+                "background_job_id": bg_id
+            }
+        else:
+            # Execute command synchronously
+            output, exit_code = session.execute(command, timeout=timeout)
+            
+            # Update system state directory
+            self.state.current_directory = session.current_directory
+            
+            # Truncate output if too long
+            if len(output) > 30000:
+                output = output[:30000] + f"\n... (output truncated, {len(output)} total characters)"
+            
+            return {
+                "output": output,
+                "exit_code": exit_code,
+                "shell_id": shell_id,
+                "working_directory": session.current_directory
+            }