Go File Handling

What is File Handling?

File handling allows programs to read from and write to files.

This is used for storing data, logs, and configuration files.

Reading Files

Use os.ReadFile() to read the contents of a file.

It returns the file data as a byte slice.

Writing Files

Use os.WriteFile() to write data to a file.

It creates the file if it does not exist or overwrites it if it does.

Appending to Files

To append data, open the file with specific flags.

This allows adding content without deleting existing data.

Creating Files

You can create a new file using os.Create().

Always close the file after using it.

Writing with File Streams

You can write data using file streams for more control.

This is useful for writing large or structured data.

Reading Line by Line

You can read files line by line using a scanner.

This is useful for large files.

Handling Errors

File operations can fail, so always check errors.

This ensures your program does not crash unexpectedly.

Why File Handling is Important

File handling is used in almost every real-world Go application.

• Logging data
• Saving user input
• Reading configuration files

Common Mistakes

Be careful with these:

• Not closing files
• Ignoring errors
• Incorrect file permissions

Practice

Create a program that writes text to a file and then reads and prints it.

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