Command Output Parsing Failure for Bang (!) Prefix Commands

Bug Description
Claude code can't see the output of the command that I launched in the terminal with the '!' prefix. I expect it could do it for helping me during bash scripting

Environment Info

• Platform: darwin
• Terminal: Apple_Terminal
• Version: 1.0.83
• Feedback ID:

Errors

[{"error":"Error: Language not supported while highlighting code, falling back to markdown: \n    at NX (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1774:1184)\n    at file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1774:912\n    at Array.map (<anonymous>)\n    at ZW (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1774:903)\n    at ZbB (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:2382:6938)\n    at SR (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:330:19859)\n    at rb (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:332:42835)\n    at ab (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:332:38356)\n    at wj (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:332:38284)\n    at aR (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:332:38138)","timestamp":"2025-08-16T14:15:38.992Z"},{"error":"Error: Language not supported while highlighting code, falling back to markdown: \n    at NX (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1774:1184)\n    at file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1774:912\n    at Array.map (<anonymous>)\n    at ZW (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1774:903)\n    at ZbB (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:2382:6938)\n    at SR (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:330:19859)\n    at Ij (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:332:3227)\n    at rb (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:332:43616)\n    at ab (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:332:38356)\n    at wj (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:332:38284)","timestamp":"2025-08-16T14:15:39.277Z"},{"error":"Error: Language not supported while highlighting code, falling back to markdown: \n    at NX (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1774:1184)\n    at file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1774:912\n    at Array.map (<anonymous>)\n    at ZW (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1774:903)\n    at fb1 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1922:690)\n    at SR (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:330:19859)\n    at rb (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:332:42835)\n    at ab (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:332:38356)\n    at wj (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:332:38284)\n    at aR (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:332:38138)","timestamp":"2025-08-16T14:19:01.495Z"},{"error":"Error: Language not supported while highlighting code, falling back to markdown: \n    at NX (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1774:1184)\n    at file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1774:912\n    at Array.map (<anonymous>)\n    at ZW (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1774:903)\n    at ZbB (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:2382:6938)\n    at SR (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:330:19859)\n    at rb (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:332:42835)\n    at ab (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:332:38356)\n    at wj (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:332:38284)\n    at aR (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:332:38138)","timestamp":"2025-08-16T14:20:53.654Z"},{"error":"Error: Language not supported while highlighting code, falling back to markdown: \n    at NX (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1774:1184)\n    at file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1774:912\n    at Array.map (<anonymous>)\n    at ZW (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1774:903)\n    at ZbB (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:2382:6938)\n    at SR (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:33

Note: Error logs were truncated.

Chat

> There is a method to start a live server from the terminal in order you can see the logs 
  while i'm acting in the interface?

⏺ Yes! You can start a simple HTTP server from the terminal to serve your files and see
  real-time logs.

⏺ Bash(python3 -m http.server 8000)
  ⎿  No (tell Claude what to do differently)

! python3 -m http.server 8000
  ⎿  Interrupted by user

> /permissions 
  ⎿  Added deny rule Bash(python3 -m http.server 8000)

# Don't run yourself "python3 -m http.server 8000". Ask me to run it
  ⎿  Good to know.

> I played with the UI. I started and then stopped the simulation. I saw the same issue

⏺ Please run this command in your terminal to start a local server:

  python3 -m http.server 8000

  Then open http://localhost:8000 in your browser. This way you'll see the console logs in
  real-time while interacting with the interface.

  Once you have it running and can see the logs, try the play/stop sequence again and let me
  know what the console shows when the vehicles disappear.

> I have just done it, as I said to you

⏺ Got it! Since you're already running the server and still seeing the issue where vehicles
  disappear when you start/stop the simulation, can you share what the console logs show when
  this happens?

  The debug logs I added should show:
  - "Vehicle data loaded: [...]"
  - "Vehicles initialized: [...]"
  - "Drawing vehicles: X" (where X is the number of vehicles)
  - Individual vehicle data for each frame

  What do you see in the console when the vehicles disappear?

> Are you not able to see the logs? I started previously the server here
  ! python3 -m http.server 8000
    ⎿  Interrupted by user

⏺ No, I can't see the logs from your browser console or the server output. I can only see what
  you explicitly share with me.

  When you interact with the interface at http://localhost:8000, could you copy and paste the
  console output (from the browser's developer tools, F12 → Console tab) that appears when the
  vehicles disappear?

  This will help me understand what's happening when you start/stop the simulation.