diff --git a/shell/library.sh b/shell/library.sh
index 52138f8..38449cc 100644
--- a/shell/library.sh
+++ b/shell/library.sh
@@ -783,3 +783,15 @@ func_secret_input(){
 	echo ""
 }
 
+
+# Check if a program is installed
+command_exists() {
+    # check if command exists and fail otherwise
+    command -v "$1" >/dev/null 2>&1
+    if [[ $? -ne 0 ]]; then
+        echo "I require $1 but it's not installed. Abort."
+        exit 1
+    fi
+}
+
+
diff --git a/shell/wait-process.sh b/shell/wait-process.sh
new file mode 100644
index 0000000..a94ee64
--- /dev/null
+++ b/shell/wait-process.sh
@@ -0,0 +1,90 @@
+#!/bin/bash
+# Shows a spinner while another command is running. Randomly picks one of 12 spinner styles.
+# @args command to run (with any parameters) while showing a spinner. 
+#       E.g. ‹spinner sleep 10›
+
+function shutdown() {
+  tput cnorm # reset cursor
+}
+trap shutdown EXIT
+
+function cursorBack() {
+  echo -en "\033[$1D"
+}
+
+function spinner() {
+  # make sure we use non-unicode character type locale 
+  # (that way it works for any locale as long as the font supports the characters)
+  local LC_CTYPE=C
+
+  local pid=$1 # Process Id of the previous running command
+
+  case $(($RANDOM % 12)) in
+  0)
+    local spin='⠁⠂⠄⡀⢀⠠⠐⠈'
+    local charwidth=3
+    ;;
+  1)
+    local spin='-\|/'
+    local charwidth=1
+    ;;
+  2)
+    local spin="▁▂▃▄▅▆▇█▇▆▅▄▃▂▁"
+    local charwidth=3
+    ;;
+  3)
+    local spin="▉▊▋▌▍▎▏▎▍▌▋▊▉"
+    local charwidth=3
+    ;;
+  4)
+    local spin='←↖↑↗→↘↓↙'
+    local charwidth=3
+    ;;
+  5)
+    local spin='▖▘▝▗'
+    local charwidth=3
+    ;;
+  6)
+    local spin='┤┘┴└├┌┬┐'
+    local charwidth=3
+    ;;
+  7)
+    local spin='◢◣◤◥'
+    local charwidth=3
+    ;;
+  8)
+    local spin='◰◳◲◱'
+    local charwidth=3
+    ;;
+  9)
+    local spin='◴◷◶◵'
+    local charwidth=3
+    ;;
+  10)
+    local spin='◐◓◑◒'
+    local charwidth=3
+    ;;
+  11)
+    local spin='⣾⣽⣻⢿⡿⣟⣯⣷'
+    local charwidth=3
+    ;;
+  esac
+
+  local i=0
+  tput civis # cursor invisible
+  while kill -0 $pid 2>/dev/null; do
+    local i=$(((i + $charwidth) % ${#spin}))
+    printf "%s" "${spin:$i:$charwidth}"
+
+    cursorBack 1
+    sleep .1
+  done
+  tput cnorm
+  wait $pid # capture exit code
+  echo "123"
+  return $?
+}
+
+("$@") &
+
+spinner $!