How to use the command `base64` (with examples)

This article will provide a step-by-step guide on how to use the base64 command, including various use cases and their corresponding explanations.

Command Description

The base64 command is used to encode and decode text or files using Base64 representation. Base64 encoding is a way to convert binary data into ASCII characters, which can be easily transmitted over text-oriented protocols such as email or HTTP.

Use case 1: Encode a file

Code:

base64 --input=plain_file

Motivation:

Encoding a file using Base64 can be useful when you need to transfer binary data over text-oriented protocols, such as when sending attachments via email.

Explanation:

• --input=plain_file: Specifies the input file to be encoded.

Example output:

SGVsbG8gd29ybGQ=

Use case 2: Decode a file

Code:

base64 --decode --input=base64_file

Motivation:

Decoding a file encoded with Base64 is necessary when you receive a Base64-encoded file and need to restore its binary data.

Explanation:

• --decode: Instructs base64 to decode the input file.
• --input=base64_file: Specifies the Base64-encoded input file to be decoded.

Example output:

Hello world!

Use case 3: Encode from stdin

Code:

echo -n "plain_text" | base64

Motivation:

Encoding text from stdin is useful when you want to encode data on the fly or integrate the command into a larger pipeline.

Explanation:

• echo -n "plain_text": Generates the text to be encoded.
• |: Pipes the output of the previous command as input to the next one.
• base64: Encodes the input received from stdin.

Example output:

cGxhaW5fdGV4dA==

Use case 4: Decode from stdin

Code:

echo -n base64_text | base64 --decode

Motivation:

Decoding a Base64-encoded text from stdin allows you to restore the original data sent in Base64 format.

Explanation:

• echo -n base64_text: Generates the Base64-encoded text to be decoded.
• |: Pipes the output of the previous command as input to the next one.
• base64 --decode: Decodes the input received from stdin.

Example output:

plain_text

Conclusion

The base64 command is a versatile tool for encoding and decoding data using Base64 representation. Whether you need to encode files or process data from stdin, understanding and utilizing these use cases will enable you to manipulate Base64 data effectively.