diff --git a/du_setup.sh b/du_setup.sh
index 47f8f84..54aacc4 100644
--- a/du_setup.sh
+++ b/du_setup.sh
@@ -1050,10 +1050,15 @@ cleanup_provider_packages() {
     fi
 }
 
+# --- (This function goes AFTER cleanup_provider_packages() and BEFORE setup_user()) ---
+
 configure_custom_bashrc() {
     local USER_HOME="$1"
     local USERNAME="$2"
     local BASHRC_PATH="$USER_HOME/.bashrc"
+    local temp_source_bashrc=""
+
+    trap 'rm -f "$temp_source_bashrc" 2>/dev/null' RETURN ERR INT TERM
 
     if ! confirm "Replace default .bashrc for '$USERNAME' with a custom one?" "n"; then
         print_info "Skipping custom .bashrc configuration."
@@ -1061,11 +1066,17 @@ configure_custom_bashrc() {
         return 0
     fi
 
-    print_info "Creating custom .bashrc for '$USERNAME'..."
-    log "Creating custom .bashrc at $BASHRC_PATH"
+    print_info "Preparing custom .bashrc for '$USERNAME'..."
 
-    local bashrc_content
-    bashrc_content=$(cat <<'EOF'
+    temp_source_bashrc=$(mktemp "/tmp/custom_bashrc_source.XXXXXX")
+    if [[ -z "$temp_source_bashrc" || ! -f "$temp_source_bashrc" ]]; then
+        print_error "Failed to create temporary file for .bashrc content."
+        log "Error: mktemp failed for bashrc source."
+        return 0
+    fi
+    chmod 600 "$temp_source_bashrc"
+
+    if ! cat > "$temp_source_bashrc" <<'EOF'; then
 # shellcheck shell=bash
 # ===================================================================
 #   Universal Portable .bashrc for Modern Terminals
@@ -2228,49 +2239,51 @@ alias commands='compgen -A function -A alias | grep -v "^_" | sort | column'
 # - Consider moving rarely-used functions to separate files
 # - Use 'time bash -i -c exit' to measure startup time
 EOF
-) # End of bashrc_content assignment
-
-    # Back up existing .bashrc if it's not the default
-    if [[ -f "$BASHRC_PATH" ]] && ! grep -q "generated by /usr/sbin/adduser" "$BASHRC_PATH" 2>/dev/null; then
-        local BASHRC_BACKUP="$BASHRC_PATH.backup_$(date +%Y%m%d_%H%M%S)"
-        print_info "Backing up existing non-default .bashrc to $BASHRC_BACKUP"
-        cp "$BASHRC_PATH" "$BASHRC_BACKUP"
-        log "Backed up existing .bashrc to $BASHRC_BACKUP"
+        print_error "Failed to write .bashrc content to temporary file $temp_source_bashrc."
+        log "Critical error: Failed to write bashrc content to $temp_source_bashrc."
+        rm -f "$temp_source_bashrc" 2>/dev/null
+        return 0
     fi
 
-    local temp_bashrc_path
-    temp_bashrc_path="/tmp/custom_bashrc_for_${USERNAME}.txt"
-    if ! printf '%s\n' "$bashrc_content" | tee "$BASHRC_PATH" > /dev/null; then
+    log "Successfully created temporary .bashrc source at $temp_source_bashrc"
+
+    local temp_fallback_path="/tmp/custom_bashrc_for_${USERNAME}.txt"
+
+    if ! tee "$BASHRC_PATH" < "$temp_source_bashrc" > /dev/null; then
         print_error "Failed to automatically write custom .bashrc to $BASHRC_PATH."
         log "Error writing custom .bashrc for $USERNAME to $BASHRC_PATH (likely permissions issue)."
 
-        if printf '%s\n' "$bashrc_content" | tee "$temp_bashrc_path" > /dev/null; then
-            chmod 644 "$temp_bashrc_path"
+        if cp "$temp_source_bashrc" "$temp_fallback_path"; then
+            chmod 644 "$temp_fallback_path"
             print_warning "ACTION REQUIRED: The custom .bashrc content has been saved to:"
-            print_warning "  ${temp_bashrc_path}"
+            print_warning "  ${temp_fallback_path}"
             print_info "After setup, please manually copy it:"
-            print_info "  sudo cp ${temp_bashrc_path} ${BASHRC_PATH}"
+            print_info "  sudo cp ${temp_fallback_path} ${BASHRC_PATH}"
             print_info "  sudo chown ${USERNAME}:${USERNAME} ${BASHRC_PATH}"
             print_info "  sudo chmod 644 ${BASHRC_PATH}"
-            log "Saved custom .bashrc content to $temp_bashrc_path for manual installation."
+            log "Saved custom .bashrc content to $temp_fallback_path for manual installation."
         else
-            print_error "Also failed to save custom .bashrc content to $temp_bashrc_path."
-            log "Critical error: Failed both writing to $BASHRC_PATH and saving to $temp_bashrc_path."
+            print_error "Also failed to save custom .bashrc content to $temp_fallback_path."
+            log "Critical error: Failed both writing to $BASHRC_PATH and copying $temp_source_bashrc to $temp_fallback_path."
         fi
     else
         if ! chown "$USERNAME:$USERNAME" "$BASHRC_PATH" || ! chmod 644 "$BASHRC_PATH"; then
             print_warning "Failed to set correct ownership/permissions on $BASHRC_PATH."
             log "Failed to chown/chmod $BASHRC_PATH"
             print_warning "ACTION REQUIRED: Please manually set ownership/permissions:"
+            print_info "  sudo cp ${temp_source_bashrc} ${BASHRC_PATH} # You might need this if the file is corrupted"
             print_info "  sudo chown ${USERNAME}:${USERNAME} ${BASHRC_PATH}"
             print_info "  sudo chmod 644 ${BASHRC_PATH}"
+            temp_source_bashrc=""
         else
             print_success "Custom .bashrc created for '$USERNAME'."
             log "Custom .bashrc configuration completed for $USERNAME."
+            rm -f "$temp_fallback_path" 2>/dev/null
         fi
-        rm -f "$temp_bashrc_path" 2>/dev/null
     fi
 
+    rm -f "$temp_source_bashrc" 2>/dev/null
+
     return 0
 }