--- /dev/null
+#!/usr/bin/ucode
+
+import { stdin, open, error } from 'fs';
+
+if (length(ARGV) == 0 && stdin.isatty()) {
+ warn("usage: b64decode [stdin|path]\n");
+ exit(1);
+}
+
+let fp = stdin;
+let source = ARGV[0];
+
+if (source) {
+ fp = open(source);
+ if (!fp) {
+ warn('b64decode: unable to open ${source}: ${error()}\n');
+ exit(1);
+ }
+}
+
+print(b64dec(fp.read("all")));
+fp.close();
+exit(0);