Pipe Anything into Claude Code

Claude Code works as a Unix citizen. Pipe anything into it:

# Analyze error logs
cat error.log | claude -p "What's causing these errors? Suggest fixes."

# Review a diff
git diff | claude -p "Review this diff for bugs and suggest improvements."

# Explain a file
cat src/complex-module.ts | claude -p "Explain this code in plain English."

# Analyze test failures
npm test 2>&1 | claude -p "Why are these tests failing? Give me the fix."

Combine with Other Tools

# Find and analyze all TODO comments
grep -rn "TODO" src/ | claude -p "Prioritize these TODOs by importance and suggest which to tackle first."

# Check for security issues in dependencies
npm audit 2>&1 | claude -p "Which of these vulnerabilities are critical and how do I fix them?"

# Analyze git history
git log --oneline -20 | claude -p "Summarize what's been worked on recently."

Output as JSON

git diff --staged | claude -p "List all changed functions" --output-format json

The -p flag makes Claude non-interactive. It reads stdin, processes it, and prints the result to stdout. Perfect for scripting.