add default terminal implementation

[QiBaobin]

it seems that most of terminal support -e option, let use it as a fallback implementation so that we can use terminal and new on other undefined terminal like alacritty, Terminal.app.

[mawww]

I am not sure how much $TERM can be used to find the actual binary of the current terminal, the TERM env var is used for terminfo resolution and common values that come to mind will not resolve correctly (say xterm-256color which would not find xterm or rxvt-unicode which would not match urxvt)

[QiBaobin]

I am not sure how much $TERM can be used to find the actual binary of the current terminal, the TERM env var is used for terminfo resolution and common values that come to mind will not resolve correctly (say xterm-256color which would not find xterm or rxvt-unicode which would not match urxvt)

That's a good point, I made another change to ensure we have '$TERM' exists using which, could you take another look?

[Screwtapello]

Do alacritty or Terminal.app even set $TERM to something that could be used to launch them?

My understanding is that most terminals set $TERM to "xterm" or "xterm-256color" for compatibility reasons, regardless of what the terminal's actual name is.

[QiBaobin]

Do alacritty or Terminal.app even set $TERM to something that could be used to launch them?

My understanding is that most terminals set $TERM to "xterm" or "xterm-256color" for compatibility reasons, regardless of what the terminal's actual name is.

I tested, alacritty works as it set TERM to 'alacritty', and some others also works based on http://jdebp.uk./Softwares/nosh/guide/TERM.html , of course there are still a lot of others don't work.

In this patch, I added this to the last to only give it a try if none of others doesn't work.

[QiBaobin]

@mawww , @Screwtapello , do you think using ps to get parent of parent of the kak client is a better idea?

ps -o 'args=' -p $(ps -o 'ppid=' -p %val{client_pid}) # the parent is the shell starting the kak, the parent of the shell would be the terminal

[QiBaobin]

don't figure out a good way, let's close it for now

[QiBaobin]

here is the logic from neofetch, it looks like complex.

get_term() {
    # If function was run, stop here.
    ((term_run == 1)) && return

    # Workaround for macOS systems that
    # don't support the block below.
    case $TERM_PROGRAM in
        "iTerm.app")    term="iTerm2" ;;
        "Terminal.app") term="Apple Terminal" ;;
        "Hyper")        term="HyperTerm" ;;
        *)              term="${TERM_PROGRAM/\.app}" ;;
    esac

    # Most likely TosWin2 on FreeMiNT - quick check
    [[ "$TERM" == "tw52" || "$TERM" == "tw100" ]] && term="TosWin2"
    [[ "$SSH_CONNECTION" ]] && term="$SSH_TTY"
    [[ "$WT_SESSION" ]]     && term="Windows Terminal"

    # Check $PPID for terminal emulator.
    while [[ -z "$term" ]]; do
        parent="$(get_ppid "$parent")"
        [[ -z "$parent" ]] && break
        name="$(get_process_name "$parent")"

        case ${name// } in
            "${SHELL/*\/}"|*"sh"|"screen"|"su"*|"newgrp") ;;

            "login"*|*"Login"*|"init"|"(init)")
                term="$(tty)"
            ;;

            "ruby"|"1"|"tmux"*|"systemd"|"sshd"*|"python"*|\
            "USER"*"PID"*|"kdeinit"*|"launchd"*|"bwrap")
                break
            ;;

            "gnome-terminal-") term="gnome-terminal" ;;
            "urxvtd")          term="urxvt" ;;
            *"nvim")           term="Neovim Terminal" ;;
            *"NeoVimServer"*)  term="VimR Terminal" ;;

            *)
                # Fix issues with long process names on Linux.
                [[ $os == Linux ]] && term=$(realpath "/proc/$parent/exe")

                term="${name##*/}"

                # Fix wrapper names in Nix.
                [[ $term == .*-wrapped ]] && {
                   term="${term#.}"
                   term="${term%-wrapped}"
                }
            ;;
        esac
    done

    # Log that the function was run.
    term_run=1
}