fish_install.sh

#!/usr/bin/env bash

set -e
set -u
set -o pipefail
set -C

ARCH=$(uname -m)
GITHUB_API_URL="https://api.github.com/repos/fish-shell/fish-shell/releases/latest"
FISH_VERSION=$(curl -sfL $GITHUB_API_URL | jq -r ".tag_name")
DOWNLOAD_URL="https://github.com/fish-shell/fish-shell/releases/download/${FISH_VERSION}/fish-${FISH_VERSION}-linux-${ARCH}.tar.xz"
INSTALL_DIR="/usr/local/bin"
INSTALL_PATH="${INSTALL_DIR}/fish"


_is_root() {
    if [[ $(id -u) -eq 0 ]]; then
        return 0
    else
        return 1
    fi
}

_execute() {
    local BASH=$(which bash)
    if ! _is_root; then
        BASH="sudo $BASH"
    fi
    $BASH -c "$@"
}

_fish_local_version() {

    $INSTALL_PATH --version | perl -nlpe  's/^(.*)\s+([\d\.]+)$/$2/'
}

install() {

    if [[ -f $INSTALL_PATH ]]; then
        echo "$INSTALL_PATH is already exists."
        exit 1
    fi
    _execute "curl -sfL $DOWNLOAD_URL | tar -C $INSTALL_DIR -pxvJf -"
}

forceinstall() {

    uninstall
    echo "nvim force install."
    echo ""
    install
}

update() {

    if [[ ! -f $INSTALL_PATH ]]; then
        echo "$INSTALL_PATH is not exists."
        exit 1
    fi
    FISH_LOCAL_VERSION=$(_fish_local_version)
    if [[ "$FISH_LOCAL_VERSION" = "$FISH_VERSION" ]];then
        echo "fish local version is $FISH_LOCAL_VERSION and fish latest version is $FISH_VERSION. skip."
        exit
    fi
    forceinstall
}

uninstall() {

    if [[ ! -f $INSTALL_PATH ]]; then
        echo "$INSTALL_PATH is not exists."
        exit 1
    fi
    _execute "rm -frv $INSTALL_PATH"
}

usage() {
    echo "Usage: $0 [install|forceinstall|update|uninstall]"
    exit 1
}

if [ $# -ne 1 ]; then
    usage
fi


COMMAND=$1
case "$COMMAND" in
  "install" ) install ;;
  "forceinstall" ) forceinstall ;;
  "update" ) update ;;
  "uninstall" ) uninstall ;;
  * )  usage;;
esac