update

config/shared/addpaths

@@ -3,13 +3,25 @@
 set -euo pipefail
 
 usage() {
-  echo "Usage: $(basename "$0") -c COMMENT_SYMBOL [-e EXCLUDE_PATTERN]... TARGET"
-  echo "  -c  Comment symbol (e.g., '#' or '//')"
+  echo "Usage: $(basename "$0") <command> [options] TARGET"
+  echo ""
+  echo "Commands:"
+  echo "  add   Add/update path comment in first 5 lines of each file"
+  echo "  undo  Remove any path comment from first 5 lines of each file"
+  echo ""
+  echo "Options:"
+  echo "  -c  Comment symbol (e.g., '#' or '//') [required for add]"
   echo "  -e  Exclude pattern (can be specified multiple times)"
-  echo "  TARGET  File or directory to process"
   exit 1
 }
 
+[[ $# -lt 1 ]] && usage
+
+cmd="$1"
+shift
+
+[[ "$cmd" != "add" && "$cmd" != "undo" ]] && usage
+
 comment_sym=""
 excludes=()
 
@@ -24,66 +36,63 @@ done
 
 shift $((OPTIND - 1))
 [[ $# -ne 1 ]] && usage
-[[ -z "$comment_sym" ]] && usage
+
+if [[ "$cmd" == "add" ]]; then
+  [[ -z "$comment_sym" ]] && {
+    echo "Error: -c is required for add" >&2
+    usage
+  }
+fi
 
 target="$(realpath "$1")"
 base_dir="$(pwd)"
 
+strip_path_comment() {
+  local file="$1"
+  awk 'NR <= 5 && /path: / { next } { print }' "$file" >"$file.tmp"
+  mv "$file.tmp" "$file"
+}
+
 process_file() {
   local file="$1"
   # shellcheck disable=SC2295
   local rel_path="${file#$base_dir/}"
-
   local path_comment="$comment_sym path: $rel_path"
 
-  # Read first two lines
-  local line1 line2
-  IFS= read -r line1 <"$file" 2>/dev/null || line1=""
-  IFS= read -r line2 < <(tail -n +2 "$file") 2>/dev/null || line2=""
+  strip_path_comment "$file"
+
+  local line1
+  IFS= read -r line1 <"$file" 2>/dev/null || line1=""
 
-  # Handle shebang case
   if [[ "$line1" =~ ^#! ]]; then
-    if [[ "$line2" == *"path: "* ]]; then
-      # Replace existing path comment on line 2
-      {
-        echo "$line1"
-        echo "$path_comment"
-        tail -n +3 "$file"
-      } >"$file.tmp"
-    else
-      # Insert new path comment after shebang
-      {
-        echo "$line1"
-        echo "$path_comment"
-        tail -n +2 "$file"
-      } >"$file.tmp"
-    fi
+    {
+      echo "$line1"
+      echo "$path_comment"
+      tail -n +2 "$file"
+    } >"$file.tmp"
   else
-    if [[ "$line1" == *"path: "* ]]; then
-      # Replace existing path comment on line 1
-      {
-        echo "$path_comment"
-        tail -n +2 "$file"
-      } >"$file.tmp"
-    else
-      # Insert new path comment at top
-      {
-        echo "$path_comment"
-        cat "$file"
-      } >"$file.tmp"
-    fi
+    {
+      echo "$path_comment"
+      cat "$file"
+    } >"$file.tmp"
   fi
 
   mv "$file.tmp" "$file"
 }
 
-if [[ -f "$target" ]]; then
-  process_file "$target"
-elif [[ -d "$target" ]]; then
-  find_cmd=(find "$target")
+dispatch() {
+  local file="$1"
+  if [[ "$cmd" == "add" ]]; then
+    process_file "$file"
+  else
+    strip_path_comment "$file"
+  fi
+}
 
-  # Always exclude hidden files and directories
-  find_cmd+=(\( -name ".*" -prune \))
+if [[ -f "$target" ]]; then
+  dispatch "$target"
+elif [[ -d "$target" ]]; then
+  find_cmd=(find "$target" \( -name ".*" -prune \))
 
   if [[ ${#excludes[@]} -gt 0 ]]; then
     find_cmd+=(-o \()
@@ -98,7 +107,7 @@ elif [[ -d "$target" ]]; then
   find_cmd+=(-o -type f -print0)
 
   while IFS= read -r -d '' file; do
-    process_file "$file"
+    dispatch "$file"
   done < <("${find_cmd[@]}")
 else
   echo "Error: $target is not a file or directory" >&2