+ if (( $# )); then
+ for x in "$@"; do
+ [[ -e "$file" ]] && $readsudo grep -q "^$x$" "$file" || $writesudo tee -a "$file"<<<"$x"
+ done
+ elif [[ ! -t 0 ]]; then
+ unset IFS
+ while read -r x; do
+ # duplicated from above
+ [[ -e "$file" ]] && $readsudo grep -q "^$x$" "$file" || $writesudo tee -a "$file"<<<"$x"
+ done
+ fi