# Large File Handling

> Large File Handling is an Agent Skill for documents published in the majiayu000/claude-skill-registry repository on GitHub: a SKILL.md instruction file an AI agent can load to do this task.

This skill should be used when the user asks about "reading large files", "file too big", "context limit", "chunking files", "offset and limit", "file causing crash", or when encountering files over 10MB. Provides strategies for safely reading large files without exhausting context.

- Skill name: `Large File Handling`
- Category: [Documents](https://www.openparable.com/skill/documents/1)
- Source: https://github.com/majiayu000/claude-skill-registry/blob/HEAD/skills/development/large-file-handling/SKILL.md
- Repository: majiayu000/claude-skill-registry (498 GitHub stars when collected)

## SKILL.md

# Large File Handling for Claude Code

## Context Limits

Claude Code has these file reading constraints:
- **25,000 tokens** maximum per file read (~100KB of text)
- **200,000 tokens** total context window
- Files over 50MB may cause system hangs

## Safe Reading Strategies

### Use Offset and Limit Parameters

Read specific portions instead of entire files:

```
Read file with offset=0 limit=500      # First 500 lines
Read file with offset=1000 limit=500   # Lines 1000-1500
```

### Search Before Reading

Find relevant sections first:
```bash
grep -n "pattern" large-file.log | head -20
```
Then read only around matching line numbers.

### Blocked File Types

Never attempt to read directly:
- **Databases**: .db, .sqlite, .sqlite3
- **Archives**: .zip, .tar, .gz, .7z
- **Binaries**: .exe, .dll, .so, .bin
- **Large media**: videos, large images

### Alternative Approaches by File Type

| File Type | Alternative |
|-----------|------------|
| SQLite DB | `sqlite3 file.db "SELECT * FROM table LIMIT 10"` |
| Large log | `tail -1000 file.log` or `grep "ERROR" file.log` |
| JSON (large) | `jq '.specific.path' file.json` |
| CSV (large) | `head -100 file.csv` or `csvtool` |
| PDF (large) | `pdftotext file.pdf - \| head -1000` |
| Minified JS | Usually not needed - read source instead |

### .claudeignore Best Practices

Add these patterns to prevent accidental reads:
```
# Binary and database
*.db
*.sqlite
*.exe
*.dll

# Large generated files
*.min.js
*.bundle.js

# Dependencies
node_modules/
vendor/
.venv/

# Build output
dist/
build/
.next/

# Logs
*.log
logs/
```

## Commands Available

- `/file-check <path>` - Check if a file is safe to read
- `/file-chunk <path>` - Get chunking strategy for large file
- `/scan-large-files [dir]` - Find problematic files in directory

## When Encountering Large Files

1. **Check size first** using `/file-check`
2. **For text files > 10MB**: Use chunking with offset/limit
3. **For logs**: Search for relevant patterns first
4. **For databases**: Use CLI tools to query
5. **For generated files**: Often not needed - read source instead

---

Source: https://www.openparable.com/skill/documents/large-file-handling (OpenParable). Cite the canonical URL above.