diff --git a/README.md b/README.md
index 45c3759..eebc571 100644
--- a/README.md
+++ b/README.md
@@ -38,7 +38,7 @@ Any feedback appreciated: [contact@artcode.re](mailto:contact@artcode.re)
 
 ## install
 <!-- markdownlint-disable MD013 MD025 -->
-`curl -s https://git.artcode.re/miaou/miaou-bash/raw/branch/main/install.sh | sudo bash && exec bash -l`
+`source <(curl -s https://git.artcode.re/miaou/miaou-bash/raw/branch/main/install.sh)`
 
 ## upgrade
 
diff --git a/install.sh b/install.sh
index 4c6995d..5983c1c 100755
--- a/install.sh
+++ b/install.sh
@@ -1,40 +1,65 @@
-#!/usr/bin/bash -E
-
+#!/usr/bin/env bash
 ## CONSTANTS
 
+#TODO: LATEST_TAG
+# LATEST_TAG=$(curl -s https://git.artcode.re/api/v1/repos/miaou/miaou-bash/tags|grep -oPm1 '{"name":".*?",' | head -n1 | cut -d'"' -f4)
+# https://git.artcode.re/miaou/miaou-bash/archive/0.3.109.tar.gz
+
 MAIN_TAR_GZ_URL="https://git.artcode.re/miaou/miaou-bash/archive/main.tar.gz"
 
 ## FUNCTIONS
 
-function bootstrap {
-  cd "$(mktemp -d)" || exit 3
-  curl -s -O $MAIN_TAR_GZ_URL
-  tar -xzf main.tar.gz --directory "$(dirname $MIAOU_BASH_DIR)"
+function upgrade {
+  echo UPGRADE
+  execute_miaou_lib self-upgrade
 }
 
-function assert_supported_distro {
-  grep -E '^ID=debian|^ID_LIKE=debian' /etc/os-release ||
-    grep -E '^ID=arch|^ID_LIKE=arch' /etc/os-release
+function install {
+  echo INSTALL
+  MIAOU_BASH_DIR=/opt/miaou-bash
+  export MIAOU_BASH_DIR
+
+  local tempfile
+  tempfile="/tmp/$(basename "$MAIN_TAR_GZ_URL")"
+  curl -so "$tempfile" $MAIN_TAR_GZ_URL
+  sudo tar -xzf "$tempfile" --directory "$(dirname "$MIAOU_BASH_DIR")"
+  rm "$tempfile"
+  execute_miaou_lib initiate
+  echo "miaou-bash successfully $deployment_type_adjective"
 }
 
-## MAIN
+function assert_supported_distro {
+  if ! grep -E '^ID=debian|^ID_LIKE=debian' /etc/os-release &&
+    ! grep -E '^ID=arch|^ID_LIKE=arch' /etc/os-release; then
+    local distro
+    distro=$(grep -oP '^ID=\K(.*)' /etc/os-release)
+    >&2 echo "unsupported GNU/Linux distribution: $distro"
+    >&2 echo 'only debian-like OR arch-like currently supported'
+    exit 2
+  fi
+}
 
-set -Eeuo pipefail
+function once_installed {
+  [[ -v MIAOU_BASH_DIR && -d "$MIAOU_BASH_DIR" &&
+    -L /etc/inputrc &&
+    "$(readlink /etc/inputrc)" == "$MIAOU_BASH_DIR"/etc/inputrc ]]
+}
 
-deployment_type_adjective="${1:-installed}"
+function execute_miaou_lib {
+  sudo -E "$MIAOU_BASH_DIR"/bin/miaou-bash "$MIAOU_BASH_DIR"/lib/"$1".bash
+}
 
-[[ "$UID" -ne 0 ]] && echo 'root privilege required' && exit 1
-! assert_supported_distro && echo 'unsupported distro: debian-like OR arch-like expected' && exit 2
+function sudo_root {
+  [[ "$UID" -ne 0 ]] && sudo -vp 'SUDO privilege required: '
+  true
+}
+## MAIN
 
-if [[ ! -v MIAOU_BASH_DIR ]]; then
-  MIAOU_BASH_DIR=/opt/miaou-bash
-  export MIAOU_BASH_DIR
-fi
+# source <(curl -s https://git.artcode.re/miaou/miaou-bash/raw/branch/main/install2.sh)
 
-if [[ -d "$MIAOU_BASH_DIR" && -L /etc/inputrc && "$(readlink /etc/inputrc)" == "$MIAOU_BASH_DIR"/etc/inputrc ]]; then
-  . "$MIAOU_BASH_DIR"/bin/miaou-bash "$MIAOU_BASH_DIR/lib/self-upgrade.bash"
-else
-  bootstrap
-  . "$MIAOU_BASH_DIR"/bin/miaou-bash "$MIAOU_BASH_DIR/lib/initiate.bash"
-  echo "miaou-bash successfully $deployment_type_adjective"
-fi
+set -Eeuo pipefail
+assert_supported_distro
+sudo_root
+deployment_type_adjective="${1:-installed}"
+if once_installed; then upgrade; else install; fi
+exec bash -l
diff --git a/install2.sh b/install2.sh
deleted file mode 100755
index 2c76d29..0000000
--- a/install2.sh
+++ /dev/null
@@ -1,66 +0,0 @@
-#!/usr/bin/env bash
-## CONSTANTS
-
-#TODO: LATEST_TAG
-# LATEST_TAG=$(curl -s https://git.artcode.re/api/v1/repos/miaou/miaou-bash/tags|grep -oPm1 '{"name":".*?",' | head -n1 | cut -d'"' -f4)
-# https://git.artcode.re/miaou/miaou-bash/archive/0.3.109.tar.gz
-
-MAIN_TAR_GZ_URL="https://git.artcode.re/miaou/miaou-bash/archive/main.tar.gz"
-
-## FUNCTIONS
-
-function upgrade {
-  echo UPGRADE
-  execute_miaou_lib self-upgrade
-}
-
-function install {
-  echo INSTALL
-  MIAOU_BASH_DIR=/opt/miaou-bash
-  export MIAOU_BASH_DIR
-
-  local tempfile
-  tempfile="/tmp/$(basename "$MAIN_TAR_GZ_URL")"
-  curl -so "$tempfile" $MAIN_TAR_GZ_URL
-  sudo tar -xzf "$tempfile" --directory "$(dirname "$MIAOU_BASH_DIR")"
-  rm "$tempfile"
-  execute_miaou_lib initiate
-
-  # source /etc/profile
-  echo "miaou-bash successfully installed"
-  exec bash -l
-}
-
-function assert_supported_distro {
-  if ! grep -E '^ID=debian|^ID_LIKE=debian' /etc/os-release &&
-    ! grep -E '^ID=arch|^ID_LIKE=arch' /etc/os-release; then
-    local distro
-    distro=$(grep -oP '^ID=\K(.*)' /etc/os-release)
-    >&2 echo "unsupported GNU/Linux distribution: $distro"
-    >&2 echo 'only debian-like OR arch-like currently supported'
-    exit 2
-  fi
-}
-
-function once_installed {
-  [[ -v MIAOU_BASH_DIR && -d "$MIAOU_BASH_DIR" &&
-    -L /etc/inputrc &&
-    "$(readlink /etc/inputrc)" == "$MIAOU_BASH_DIR"/etc/inputrc ]]
-}
-
-function execute_miaou_lib {
-  sudo -E "$MIAOU_BASH_DIR"/bin/miaou-bash "$MIAOU_BASH_DIR"/lib/"$1".bash
-}
-
-function sudo_root {
-  [[ "$UID" -ne 0 ]] && sudo -vp 'SUDO privilege required: '
-  true
-}
-## MAIN
-
-# source <(curl -s https://git.artcode.re/miaou/miaou-bash/raw/branch/main/install2.sh)
-
-set -Eeuo pipefail
-assert_supported_distro
-sudo_root
-if once_installed; then upgrade; else install; fi