malformed base64 input after following instructions

[ghostbuster91]

Provided command to extract base64 armored gpg key outputs on my machine additional % character at the end.

gpg --armor --export-secret-keys $LONG_ID | base64 -w0

My system is:

Ubuntu 20.04.3 LTS
>  gpg --version
gpg (GnuPG) 2.2.19
libgcrypt 1.8.5

It works as expected when calling base64 without -w0.
It seems that -w0 always add % whenever the input doesn't end with a new line.

❯ echo kasper | base64 -w0
a2FzcGVyCg==%                                                                   
~                                                                      
❯ echo kasper | base64    
a2FzcGVyCg==

I'm sure that there was a reason to add that flag to the instruction, so I am not suggesting removing it until we figure out whether it is really redundant.

By creating this issue I want to at least raise awareness for people to check output of their base64 command before they waste many hours debugging publishing.

[ghostbuster91]

It seems that this is caused by my shell - zsh which always adds % when output doesn't end with a new line. https://unix.stackexchange.com/questions/167582/why-zsh-ends-a-line-with-a-highlighted-percent-symbol

This also applies to fish

[olafurpg]

Thank you for reporting and identifying the root cause. I’d be happy to merge a PR updating the readme with separate instructions for Ubuntu+zsh/fish