gnvim.sh

#!/bin/sh

term_cmd="x-terminal-emulator"
no_tmux=""
nv_cmd="/usr/bin/nvim"
class="gnvim"
opencmd="edit"

config_dir="${XDG_CONFIG_HOME:-${HOME}/.config}/gnvim"
config_file="${config_dir}/configrc"

if [ ! -f "$config_file" ]; then
    if [ ! -d "$config_dir" ]; then
        mkdir -p "$config_dir"
    fi
    cat << __HEREDOC__ > "$config_file"
# vim: ft=sh
# gnvim wrapper config file

# terminal command
term_cmd="${term_cmd}"

# neovim command
nv_cmd="${nv_cmd}"

# open command
# used internally by neovim to open a file if not using tmux
# supported values: edit, tabedit, split, vsplit, drop
opencmd="${opencmd}"

# gnvim class
class="${class}"

# do not use tmux for regular operation
# setting this to anything will take effect
no_tmux="${no_tmux}"
__HEREDOC__
fi

# loading the config here means the default config is already present and the user is not able to
# overwrite anything defined after this point.
. "$config_file"

myname="${0##*/}"

# cuz $UID is not POSIX ¯\_(ツ)_/¯
# but it may be defined in the environment
if [ -z "$UID" ]; then
  # result of: id -u $USER
  UserID=$(id -u "$USER")
else
  UserID="$UID"
fi

case "$1" in
    class|-c|--class)
        shift
        class="$1"
        shift
        ;;
    help|-h|--help)
        printf '%s\n\t%s\n' "${myname}:" \
                            "nvim terminal wrapper"
        printf '%s\n\t%s\n' "Version:" "@VERSION@"
        printf '%s\n\t%s\n' "Usage:" \
                            "${myname} -h | [ --class NAME ] [ nvim flags and files ]"
        printf '%s\n\t%s\n' "    -h" \
                            "print out this help message, 'help' and '--help' are supported too"
        printf '%s\n\t%s\n\t%s%s\n' \
                            "    --class NAME" \
                            "sets terminal '-name' and '-T' flags to NAME, sets tmux-nvim" \
                            "--session-id to NAME, sets runfile as " \
                            "'/var/run/user/ID/NAME/NAME.lock'"
        printf '\n'
        printf '%s\n\t%s\n' "Config:" "$config_file"
        exit 0
        ;;
esac

run_dir="${XDG_RUNTIME_DIR:-/run/user/${UserID}}/${class}"
run_file="${run_dir}/${class}.lock"
p_file="${run_dir}/${class}.pipe"

# unix command line like booleans

# Type: int
# value: 0
b_true=0
# Type: int
# value: 1
b_false=1

# check if directory is empty
# return type: int
# return values:
#     empty     b_true
#     non empty b_false
# taken from:
#     https://superuser.com/questions/352289/bash-scripting-test-for-empty-directory/830902#830902
is_empty() {
    test -e "$1/"* 2>/dev/null
    case $? in
        1)   return "$b_true" ;;
        *)   return "$b_false" ;;
    esac
}

cleanup() {
    if [ -r "$run_file" ]; then
        rm "$run_file" 2>/dev/null
    fi
    if is_empty "$run_dir"; then
        rmdir "$run_dir" 2>/dev/null
    fi
}

trap cleanup EXIT

if [ -f "$run_file" ]; then
    hasterm="$b_true"
    date +"[%F %T]: ${myname} called." >> "$run_file"
else
    hasterm="$b_false"
    if [ ! -d "$run_dir" ]; then
        mkdir -p "$run_dir"
    fi
    date +"[%F %T]: ${myname} called." > "$run_file"
fi

if [ ! -f "$run_file" ]; then
    exit 1
fi
if [ "$hasterm" -eq "$b_true" ]; then
    if [ -z "$no_tmux" ]; then
        exec tmux-nvim --session-id "$class" "$@"
    else
        case "$opencmd" in
            edit|tabedit|split|vsplit|drop)
                : # do nothing, we just accept those values
                ;;
            *) # fallback to default if not a supported command
                opencmd="edit"
                ;;
        esac
        exec nvim --server "$p_file" --remote-send "<C-\\><C-N>:${opencmd} ${*}<CR>"
    fi
else
    if [ -z "$no_tmux" ]; then
        $term_cmd -name "$class" -title "$class" -e tmux-nvim --session-id "$class" "$@"
    else
        $term_cmd -name "$class" -title "$class" -e $nv_cmd --listen "$p_file" "$@"
    fi
fi