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agents-and-tools/tool-use/bash-tool.md

Changed on 2026-02-11 10:56:44 EST

Unified Diff

--- a/agents-and-tools/tool-use/bash-tool.md
+++ b/agents-and-tools/tool-use/bash-tool.md
@@ -40,15 +40,10 @@
 response = client.messages.create(
     model="claude-opus-4-6",
     max_tokens=1024,
-    tools=[
-        {
-            "type": "bash_20250124",
-            "name": "bash"
-        }
-    ],
+    tools=[{"type": "bash_20250124", "name": "bash"}],
     messages=[
         {"role": "user", "content": "List all Python files in the current directory."}
-    ]
+    ],
 )
 ```
 
@@ -123,7 +118,9 @@
 {"command": "pip install requests"}
 
 # 2. Create script
-{"command": "cat > fetch_joke.py << 'EOF'\nimport requests\nresponse = requests.get('https://official-joke-api.appspot.com/random_joke')\njoke = response.json()\nprint(f\"Setup: {joke['setup']}\")\nprint(f\"Punchline: {joke['punchline']}\")\nEOF"}
+{
+    "command": "cat > fetch_joke.py << 'EOF'\nimport requests\nresponse = requests.get('https://official-joke-api.appspot.com/random_joke')\njoke = response.json()\nprint(f\"Setup: {joke['setup']}\")\nprint(f\"Punchline: {joke['punchline']}\")\nEOF"
+}
 
 # 3. Run script
 {"command": "python fetch_joke.py"}
@@ -144,16 +141,17 @@
     import subprocess
     import threading
     import queue
-    
+
+
     class BashSession:
         def __init__(self):
             self.process = subprocess.Popen(
-                ['/bin/bash'],
+                ["/bin/bash"],
                 stdin=subprocess.PIPE,
                 stdout=subprocess.PIPE,
                 stderr=subprocess.PIPE,
                 text=True,
-                bufsize=0
+                bufsize=0,
             )
             self.output_queue = queue.Queue()
             self.error_queue = queue.Queue()
@@ -165,9 +163,9 @@
     ```python
     def execute_command(self, command):
         # Send command to bash
-        self.process.stdin.write(command + '\n')
+        self.process.stdin.write(command + "\n")
         self.process.stdin.flush()
-        
+
         # Capture output with timeout
         output = self._read_output(timeout=10)
         return output
@@ -184,12 +182,12 @@
             else:
                 command = content.input.get("command")
                 result = bash_session.execute_command(command)
-            
+
             # Return result to Claude
             tool_result = {
                 "type": "tool_result",
                 "tool_use_id": content.id,
-                "content": result
+                "content": result,
             }
     ```
   </Step>
@@ -198,11 +196,11 @@
     ```python
     def validate_command(command):
         # Block dangerous commands
-        dangerous_patterns = ['rm -rf /', 'format', ':(){:|:&};:']
+        dangerous_patterns = ["rm -rf /", "format", ":(){:|:&};:"]
         for pattern in dangerous_patterns:
             if pattern in command:
                 return False, f"Command contains dangerous pattern: {pattern}"
-        
+
         # Add more validation as needed
         return True, None
     ```
@@ -282,11 +280,7 @@
 def execute_with_timeout(command, timeout=30):
     try:
         result = subprocess.run(
-            command, 
-            shell=True, 
-            capture_output=True, 
-            text=True, 
-            timeout=timeout
+            command, shell=True, capture_output=True, text=True, timeout=timeout
         )
         return result.stdout + result.stderr
     except subprocess.TimeoutExpired:
@@ -303,7 +297,7 @@
 commands = [
     "cd /tmp",
     "echo 'Hello' > test.txt",
-    "cat test.txt"  # This works because we're still in /tmp
+    "cat test.txt",  # This works because we're still in /tmp
 ]
 ```
 
@@ -314,9 +308,9 @@
 Truncate very large outputs to prevent token limit issues:
 ```python
 def truncate_output(output, max_lines=100):
-    lines = output.split('\n')
+    lines = output.split("\n")
     if len(lines) > max_lines:
-        truncated = '\n'.join(lines[:max_lines])
+        truncated = "\n".join(lines[:max_lines])
         return f"{truncated}\n\n... Output truncated ({len(lines)} total lines) ..."
     return output
 ```
@@ -328,6 +322,7 @@
 Keep an audit trail of executed commands:
 ```python
 import logging
+
 
 def log_command(command, output, user_id):
     logging.info(f"User {user_id} executed: {command}")
@@ -343,9 +338,12 @@
 def sanitize_output(output):
     # Remove potential secrets or credentials
     import re
+
     # Example: Remove AWS credentials
-    output = re.sub(r'aws_access_key_id\s*=\s*\S+', 'aws_access_key_id=***', output)
-    output = re.sub(r'aws_secret_access_key\s*=\s*\S+', 'aws_secret_access_key=***', output)
+    output = re.sub(r"aws_access_key_id\s*=\s*\S+", "aws_access_key_id=***", output)
+    output = re.sub(
+        r"aws_secret_access_key\s*=\s*\S+", "aws_secret_access_key=***", output
+    )
     return output
 ```