CheatSheet for a new shell script

cat /etc/centos-release

env_file="./.env.$1"
shift
args=$@ # 나머지는 arg에 할당

# Check branch name
if [ -z "$1" ]; then
  echo "usage: git-finish <refspec>"; exit 1
fi

IP=$1
# 없으면 클립보드 확인
if [ -z "$IP" ] && [ -t 0 ]; then
  IP="$(pbpaste)"
fi
# 없으면 파이프라인
if [ -z "$IP" ]; then
  IP=$(</dev/stdin)
fi

if [ -z "$centos_version" ] || [ -z "$nginx_version" ]; then
  echo
  echo "Please enter a valid version."
  exit 1
fi

isNginx=false

# https://askubuntu.com/a/1716
PS3='Please enter your choice: '
options=("Nginx" "Nginx(b)")
select opt in "${options[@]}"; do
  case $opt in
    "Nginx") isNginx=true; break;;
    "Nginx(b)") isNginxB=true; break;;
    *) echo "invalid option $REPLY";;
  esac
done

echo $isNginx
echo $isNginxB

exit;

if [[ $1 =~ ^(local|alpha|beta)$ ]]; then
  echo "env is valid(local, alpha, beta)"
fi

if [[ ! $1 =~ ^(local|alpha|beta)$ ]]; then
  echo "not supported env: " $1
  exit 1
fi

echo '$(tput bold)git$(tput sgr0)'

if test ! $(which brew); then
  echo "  Installing Homebrew for you."
  ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)" > /tmp/homebrew-install.log
fi

is_executable() {
    local bin=$(command -v "$1" 2>/dev/null)
    if [[ ! $bin == "" && -x $bin ]]; then
        return 0
    else
        return 1
    fi
}


if is_executable $1 ; then echo "true"; else echo "false"; fi

function print_download_link() {
  echo "Please check the version"
  echo "  nginx: http://nginx.org/en/download.html"
  echo
}

print_download_link

function isExist(){
    local path=$1
    if [ -f $path ]; then
        return 0 # true
    else
        return 1 # false
    fi
}

if [ $? -ne 0 ]; then
  echo "Login failed"; exit 1
fi

if [ $? -eq 0 ]; then
  echo "Login succeeded"; exit 1
fi

# 응답값이 0이 아니면 종료
[ $? -eq 0 ]  || exit 1

echo Install all AppStore Apps at first!
read -p "Press any key to continue... " -n1 -s
echo ""

read -r -p "Do you wanna install git? [y/n] " res
if [[ "$res" =~ ^(yes|y)$ ]]; then
  ln -sfv "$DOTFILES_DIR/git/.gitconfig" ~
  ln -sfv "$DOTFILES_DIR/git/.gitignore_global" ~
fi

read -p "Are you sure? " -n 1
[[ ! $REPLY =~ ^[Yy]$ ]] && exit 1

if [ -z "$DOTFILES_DIR" ]; then
    echo -e "$(tput setaf 1)$(tput bold)DOTFILES_DIR doesn't exist.$(tput sgr0)" && exit 1
fi

sudo -v

ln -sfv "$DOTFILES_DIR/.npmrc" ~

if [ 조건식 ]; then
    echo "case 1"
elif [ $val -eq 12 ]; then # val == 12
    echo "case 2"
else
    echo "case 3"
fi

# if 조건안에 사용자 함수 2개 사용하는 경우
if isExist $path && ! isEmpty $path; then
    echo "test"
fi

# https://stackoverflow.com/questions/13617843/unary-operator-expected

if [ "$env" = "real" ]; then
  echo ""
fi

if [[ $env = "real" ]]; then
  echo ""
fi

if [ "$BUILD_ENV" = "real" ] || [ "$BUILD_ENV" = "beta" ]; then
  npm run build-prod
else
  npm run build
fi

ITEMS=("item1" "item2" "item3")
for item in "${ITEMS[@]}"
do
    echo $item
done

ITEMS=("item1" "item2" "item3")
for (( index=0; index<${#ITEMS[*]}; index++ ))
do
    echo ${ITEMS[$index]}
done

NGINX_PID=$(cat $DIR_NGINX/logs/nginx.pid)

source ./common.sh
. ./common.sh

BASEDIR=$(dirname "$0")
env_file="$BASEDIR/.env.$1"

# Import the env_file
set -a
source $env_file
set +a

# 가능한 sed 버전 확인 필요함
sed -i '1s/^/# This config was generated by the build script using envsubst\n/' $BASEDIR/nginx.conf

# for macos
$ pbpaste > file.md

"${parameter}"