Make posix sh compatible

installer.sh

@@ -1,9 +1,6 @@
-#!/usr/bin/env bash
+#!/usr/bin/env sh
 
-shopt -s extglob
-set -o errtrace
-set -o errexit
-set -o pipefail
+set -eu
 
 install() {
   BINARY_NAME="crib"
@@ -43,12 +40,13 @@ install() {
 
   GITHUB_URL="https://github.com/SyedM-dev/crib/releases/download/$VERSION/crib-linux-x86_64-ruby$RUBY_VERSION"
 
-  missing=()
-  command -v ruby >/dev/null 2>&1 || missing+=("ruby")
-  ldconfig -p | grep libmagic >/dev/null 2>&1 || missing+=("libmagic")
+  missing_ruby=""
+  missing_magic=""
+  command -v ruby >/dev/null 2>&1 || missing_ruby="ruby"
+  ldconfig -p | grep libmagic >/dev/null 2>&1 || missing_magic="libmagic"
 
-  if [ ${#missing[@]} -ne 0 ]; then
-    echo "Missing dependencies: ${missing[*]}"
+  if [ -n "$missing_ruby" ] || [ -n "$missing_magic" ]; then
+    echo "Missing dependencies: ${missing_ruby} ${missing_magic}"
     echo "Install them using your package manager:"
     echo "Ubuntu/Debian: sudo apt install ruby libmagic1"
     echo "Arch: sudo pacman -S ruby file"
@@ -58,7 +56,7 @@ install() {
 
   echo "Installing Crib (Ruby $RUBY_VERSION)"
 
-  echo "Install locally ~/.local/bin or globally /usr/bin? [l/g]"
+  echo "Install locally (~/.local/bin) or globally (/usr/bin)? [l/g]"
   read -r choice
   case "$choice" in
   l | L)