day2/vhdl: allow script to be run from outside its basedir

day2/vhdl/run.sh

@@ -1,11 +1,13 @@
-#!/usr/bin/env sh
+#!/usr/bin/bash
 
 set -eu
 
-INPUT=$1
+INPUT=$(readlink --canonicalize-existing "$1")
 MODE=${2:-}
 GHDLFLAGS="--std=08 --workdir=workdir"
 
+cd "$(dirname "${BASH_SOURCE[0]}")"
+
 mkdir -p workdir
 
 if [[ $MODE = "--synth" ]]; then