Terminal QR Code with Unicode characters


A wrapper around Text::QRCode to print QR codes on the terminal.

So it seems that Text::QRCode bite the XS bullet to interface with libqrencode and has then been used by a lot of modules (including Term::QRCode, introduced here).

The output of that module is a bit weird, in that it is a 2-dimensional matrix (array of arrays) where each cell contains a single character, that can be either a star * or a blank space.

I think it’s weird because I would have expected…

  • … arrays of 1 and 0 (or otherwise true and false values), OR
  • … an array of strings for each line, OR
  • … a single string with nelines inside.


I thought to use the Unicode characters discovered from QRcode.show to produce something good for the terminal:

Local version here.

The input is the encoded form produced by Text::QRCode, and the output is an array of lines.

A few remarks:

  • each pair if input lines of pixels is encoded into a single line of characters, to account for the difference in width vs. height in the terminal (this is somehow the opposite choice taken by Term::QRCode, where each input pixel is represented by two characters);
  • we’re adding the quiet zone around the produced output, to avoid confusing the decoders.

Example result:

example QR Code in the terminal

Pretty neat, uh?

I guess it’s all for today… stay safe folks!

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