How to use the command qrencode (with examples)

QR codes are widely used in various industries for efficient and convenient data transfer. The qrencode command is a powerful tool that allows users to generate QR codes from strings or input files. It supports various output formats like PNG and EPS, as well as different terminal printing options.

Use case 1: Convert a string to a QR code and save to an output file

Code:

qrencode -o path/to/output_file.png string

Motivation: This use case is useful when you need to generate a QR code for a specific string and save it as an image file. It can be handy for creating QR codes for URLs, contact information, or any other text-based data that you want to share digitally or print.

Explanation:

• qrencode: The main command that generates the QR code.
• -o path/to/output_file.png: Specifies the output file path and format. In this example, the output file is saved as a PNG image at the specified path.
• string: The input text that will be converted into the QR code.

Example output: The command will generate a PNG image file at the specified path (e.g., path/to/output_file.png) containing the QR code representing the input string.

Use case 2: Convert an input file to a QR code and save to an output file

Code:

qrencode -o path/to/output_file.png -r path/to/input_file

Motivation: This use case is beneficial when you have a file containing information that you want to convert into a QR code and save it for future use. It can be helpful when sharing confidential information like Wi-Fi credentials or encrypting a text file.

Explanation:

• qrencode: The main command that generates the QR code.
• -o path/to/output_file.png: Specifies the output file path and format. In this example, the QR code will be saved as a PNG image.
• -r path/to/input_file: Specifies the input file that contains the data to be converted into the QR code. The content of the file will be transformed into the QR code.

Example output: The command will generate a PNG image file at the specified path (e.g., path/to/output_file.png) containing the QR code representing the content of the input file.

Use case 3: Convert a string to a QR code and print it in terminal

Code:

qrencode -t ansiutf8 string

Motivation: Sometimes, you may want to quickly view the generated QR code directly in your terminal without the need to save it as a file. This use case is especially handy when you are working in a text-based environment or need to share the QR code with someone in real-time.

Explanation:

• qrencode: The main command that generates the QR code.
• -t ansiutf8: Specifies the output type as ANSI UTF-8, which allows the QR code to be displayed in the terminal using ASCII characters.
• string: The input text that will be converted into the QR code.

Example output: The command will output the QR code representation of the input string directly in the terminal using ASCII characters.

Use case 4: Convert input from pipe to a QR code and print it in terminal

Code:

echo string | qrencode -t ansiutf8

Motivation: This use case enables users to directly pipe the input from another command or source and generate the QR code in the terminal. It provides flexibility and convenience when dealing with dynamic or continuously changing data.

Explanation:

• echo string: Uses the echo command to provide the input string as output.
• |: The pipe operator redirects the output from the previous command as the input to the subsequent command.
• qrencode: The main command that generates the QR code.
• -t ansiutf8: Specifies the output type as ANSI UTF-8 for displaying the QR code in the terminal using ASCII characters.

Example output: The command will receive the input string from the echo command, generate the QR code representation, and display it directly in the terminal using ASCII characters.

Conclusion:

The qrencode command is a flexible and versatile tool that allows users to generate QR codes easily. By providing various options for output formats and terminal printing, it caters to a wide range of use cases. Whether you need to save QR codes as image files, view them in the terminal, or pipe input from other commands, qrencode has you covered. Start generating QR codes effortlessly with this powerful command.