Add bbb: a smart wraper around base64 -d

terminal/README.md

@@ -3,3 +3,4 @@
 Terminal helper programs.
 
 * `copy.sh`: Copy the contents of a file to the clipboard.
+* `bbb.sh`: A smart wrapper for base64 decoding.

terminal/bbb.sh

@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+# A smart wrapper for base64 decoding.
+
+set -euo pipefail
+
+stderr() {
+    echo "${@}" 1>&2
+}
+
+fail() {
+    stderr "${1}"
+    stderr ""
+    stderr "Exiting …"
+    exit "${2:-1}"
+}
+
+missing_dependencies=false
+declare -r dependencies=(
+  base64
+)
+for dep in "${dependencies[@]}"; do
+  if ! command -v "${dep}" &> /dev/null; then
+    stderr "❌ ERROR: Missing dependency ${dep}"
+    missing_dependencies=true
+  fi
+done
+if ${missing_dependencies}; then
+  fail 'Please install the missing dependencies!'
+fi
+
+if [[ $# -eq 0 ]]; then
+  # no args => stdin
+  base64 -d ; echo
+else
+  echo -n "${*}" | base64 -d ; echo
+fi