clean dead links

.gitignore

@@ -2,3 +2,5 @@
 .devenv/
 
 .pre-commit-config.yaml
+
+.plowcache

flake.nix

@@ -39,6 +39,7 @@
             pkgs.lib.mkIf (devenvRootFileContent != "") devenvRootFileContent;
 
           env.PLOW_FROM = "./home";
+          env.PLOW_CACHE = "./.plowcache";
 
           imports = [
             ./devenv.nix

plow/plow.bash

@@ -4,9 +4,30 @@ set -o errexit
 set -o nounset
 set -o pipefail
 
+progname="$0"
+
+error() {
+  local line
+  for line in "$@"; do
+    echo "$progname: $line" 1>&2
+  done
+
+  exit 1
+}
+
 shopt -s nullglob globstar
 
-opts=$(getopt --options f:t:Fivm: --longoptions=from:,to:,force,interactive,verbose,directory-mode: --name "$0" -- "$@")
+if [[ ! -v PLOW_CACHE ]]; then
+  PLOW_CACHE=.plowcache
+fi
+
+opts=$(
+  getopt \
+    --options f:t:Fivm: \
+    --longoptions from:,to:,force,interactive,verbose,directory-mode: \
+    --name "$0" \
+    -- "$@"
+)
 
 eval set -- "$opts"
 
@@ -14,6 +35,7 @@ from=${PLOW_FROM:-$PWD}
 to=${PLOW_TO:-$HOME}
 lnflags=()
 mkdirflags=()
+rmflags=()
 while true; do
   case "$1" in
   -f | --from)
@@ -26,15 +48,18 @@ while true; do
     ;;
   -F | --force)
     lnflags+=(--force)
+    rmflags+=(--force)
     shift
     ;;
   -i | --interactive)
     lnflags+=(--interactive)
+    rmflags+=(--interactive)
     shift
     ;;
   -v | --verbose)
     lnflags+=(--verbose)
     mkdirflags+=(--verbose)
+    rmflags+=(--verbose)
     shift
     ;;
   -m | --directory-mode)
@@ -62,13 +87,34 @@ fi
 
 shopt -s dotglob
 
+cache=()
+if [[ -n "$PLOW_CACHE" ]]; then
+  if [[ -e "$PLOW_CACHE" ]]; then
+    while IFS= read -r link; do
+      cache+=("$link")
+    done < "$PLOW_CACHE"
+  fi
+
+  : > "$PLOW_CACHE"
+fi
+
 for choice in "${choices[@]}"; do
   prefix=$from/$choice
   for target in "$prefix"/**/*; do
     if [[ -f "$target" ]]; then
       link=$to${target#"$prefix"}
-      mkdir --parents "${mkdirflags[@]}" -- "$(dirname -- "$link")"
+      parent=$(dirname -- "$link")
+      mkdir --parents "${mkdirflags[@]}" -- "$parent"
       ln --symbolic "${lnflags[@]}" -- "$target" "$link"
+      if [[ -n "$PLOW_CACHE" ]]; then
+        echo "$link" >> "$PLOW_CACHE"
+      fi
     fi
   done
 done
+
+for link in "${cache[@]}"; do
+  if [[ -L "$link" && ! -f "$link" ]]; then
+    rm "${rmflags[@]}" -- "$link"
+  fi
+done