Lesson 6Tools

File Operations

Read, Write, Edit

Read

Reads files, images, PDFs and notebooks

Write

Creates new files or completely replaces

Edit

Precise string replacements in existing files

Read — File Reading

The Read tool reads file contents and can handle various formats:

Text files.ts, .js, .py, .md, etc.

Images.png, .jpg, .gif, .webp

PDF.pdf

Jupyter Notebooks.ipynb

JSON/YAML.json, .yaml, .yml

# Usage examples:

> Read the file src/auth.ts

> Show me the screenshot error.png

> Analyze the PDF document

📖 Read can read up to 2000 lines by default. For larger files, use offset and limit.

Edit — Precise Editing

Edit replaces specific strings in a file. Requires exact text match:

# Claude executes:

Edit file: src/utils.ts

- old_string: "return null;"

+ new_string: "return data ?? null;"

When to use

• Fixing bugs
• Adding imports
• Refactoring functions
• Updating constants

Limitations

• old_string must be unique
• File must exist
• Requires prior Read

Write — File Creation

Write creates a new file or completely overwrites an existing one:

> Create a new Button component

Write file: src/components/Button.tsx

import React from 'react'; export const Button = ({ children }) => { return <button>{children}</button>; };

⚠️ Write completely replaces file contents. Use Edit for modifying existing files.

Edit vs Write: When to Use Which

Edit

Precise changes in existing file

Examples:

• Fix bug in function
• Add import
• Rename variable

✓ Shows diff, Safe, Preserves formatting

✗ Only for existing files

Write

Creating new file or complete replacement

Examples:

• Create new component
• Generate config
• Write test from scratch

✓ For new files, Full control

✗ Overwrites everything, Need to be careful

Best Practices

1.Claude always reads file before editing — this ensures accuracy
2.Prefer Edit for existing files — it's safer and shows diff
3.Use Write only for new files or complete regeneration
4.For large files, specify particular lines or functions

This lesson is part of a structured LLM course.

My Learning Path

Lesson 6Tools

File Operations

Read, Write, Edit

Read

Reads files, images, PDFs and notebooks

Write

Creates new files or completely replaces

Edit

Precise string replacements in existing files

Read — File Reading

The Read tool reads file contents and can handle various formats:

Text files.ts, .js, .py, .md, etc.

Images.png, .jpg, .gif, .webp

PDF.pdf

Jupyter Notebooks.ipynb

JSON/YAML.json, .yaml, .yml

# Usage examples:

> Read the file src/auth.ts

> Show me the screenshot error.png

> Analyze the PDF document

📖 Read can read up to 2000 lines by default. For larger files, use offset and limit.

Edit — Precise Editing

Edit replaces specific strings in a file. Requires exact text match:

# Claude executes:

Edit file: src/utils.ts

- old_string: "return null;"

+ new_string: "return data ?? null;"

When to use

• Fixing bugs
• Adding imports
• Refactoring functions
• Updating constants

Limitations

• old_string must be unique
• File must exist
• Requires prior Read

Write — File Creation

Write creates a new file or completely overwrites an existing one:

> Create a new Button component

Write file: src/components/Button.tsx

import React from 'react'; export const Button = ({ children }) => { return <button>{children}</button>; };

⚠️ Write completely replaces file contents. Use Edit for modifying existing files.

Edit vs Write: When to Use Which

Edit

Precise changes in existing file

Examples:

• Fix bug in function
• Add import
• Rename variable

✓ Shows diff, Safe, Preserves formatting

✗ Only for existing files

Write

Creating new file or complete replacement

Examples:

• Create new component
• Generate config
• Write test from scratch

✓ For new files, Full control

✗ Overwrites everything, Need to be careful

Best Practices

1.Claude always reads file before editing — this ensures accuracy
2.Prefer Edit for existing files — it's safer and shows diff
3.Use Write only for new files or complete regeneration
4.For large files, specify particular lines or functions

This lesson is part of a structured LLM course.

My Learning Path