go-isatty VS termenv

Also, check on start, if you are in terminal (you might want to use isatty C analog like go-isatty), then run usage function instead of asking for password (basically simple run with no argument or stdin, - it shouldn't ask for password and later throw a garbage to a terminal but instead show "help" since there no input stream, not file to encrypt/decrypt)

Note, you also need to handle piping to other programs or sending output to a file. See the logic in https://github.com/fatih/color/blob/master/color.go, https://github.com/mattn/go-colorable and https://github.com/mattn/go-isatty.

For example: https://github.com/muesli/termenv // Clear the visible portion of the terminal output := termenv.NewOutput(os.Stdout) output.ClearScreen()

Why not let termenv do the hard part of making this portable across terminals? It also supports lesser-known conventions like NO_COLOR.

Termenv

Look, you and I may have sane ANSI 16 colours, but it’ll be a very significant fraction of people that don’t (and almost no one will customise the next 240 colours). Remember things like that there’s a fairly high chance that blue is almost invisible against black, and even bright blue’s contrast is commonly much too low—to say nothing of the limited palette range.

But what this program is doing is using termenv’s HasDarkBackground function to decide whether the terminal is light or dark, and is then specifying RGB colours. I’d guess that it’ll try to guess whether to use 16 colours, 256 colours or 24-bit colour, but I don’t know. But the way it figures out the terminal’s background colour… ugh. Some terminals will support it, but for many it’ll fail and just assume black. Looks like on unix you could set an environment variable COLORFGBG to override this, https://github.com/muesli/termenv/blob/6bb55115565c27f4cc681..., but if you’re on Windows, tough luck, apparently you’re not allowed to have run `color f0` (Command Prompt) or similar: https://github.com/muesli/termenv/blob/537e36cb0472a69a3c828....

The simple fact of the matter is that there are no particularly good solutions for handling colour in terminals if you want the colours to cohere and map to real-world colour understanding, which is what something like this would prefer to be able to do.