diff --git a/src/cmd_line.rs b/src/cmd_line.rs
index e7f6d55..c7b9b71 100644
--- a/src/cmd_line.rs
+++ b/src/cmd_line.rs
@@ -48,6 +48,7 @@ fn to_cmd_line_args<'a>(tup: &(ArgType, &'a str))
 				.help(help)
 		];
 	}
+	// TODO: Help is redundant.
 	vec![match arg {
 		ArgType::InputMapPath =>
 			Arg::with_name("input_map")
@@ -76,6 +77,11 @@ fn to_cmd_line_args<'a>(tup: &(ArgType, &'a str))
 				a
 			}
 		},
+		ArgType::Nodes =>
+			Arg::with_name("nodes")
+				.long("nodes")
+				.min_values(1)
+				.help(help),
 		ArgType::NewNode =>
 			Arg::with_name("new_node")
 				.takes_value(true)
@@ -169,6 +175,8 @@ fn parse_cmd_line_args() -> anyhow::Result<InstArgs> {
 		offset: sub_matches.values_of("offset").map(arg_to_pos).transpose()
 			.context("Invalid offset value")?,
 		node: sub_matches.value_of("node").map(str::to_string),
+		nodes: sub_matches.values_of("nodes").iter_mut().flatten()
+			.map(str::to_string).collect(),
 		new_node: sub_matches.value_of("new_node").map(str::to_string),
 		item: sub_matches.value_of("item").map(str::to_string),
 		new_item: sub_matches.value_of("new_item").map(str::to_string),
diff --git a/src/commands/clone.rs b/src/commands/clone.rs
index ccf4d06..2e34159 100644
--- a/src/commands/clone.rs
+++ b/src/commands/clone.rs
@@ -17,7 +17,7 @@ fn clone(inst: &mut InstBundle) {
 	let offset = inst.args.offset.unwrap();
 	let dst_area = src_area + offset;
 	let mut keys = query_keys(&mut inst.db, &inst.status,
-		Vec::new(), Some(dst_area), false, true);
+		&[], Some(dst_area), false, true);
 
 	// Sort blocks according to offset such that we don't read blocks that
 	// have already been written.
diff --git a/src/commands/delete_blocks.rs b/src/commands/delete_blocks.rs
index 250c2e1..8a5d678 100644
--- a/src/commands/delete_blocks.rs
+++ b/src/commands/delete_blocks.rs
@@ -5,8 +5,8 @@ use crate::utils::query_keys;
 
 
 fn delete_blocks(inst: &mut InstBundle) {
-	let keys = query_keys(&mut inst.db, &inst.status, Vec::new(),
-		inst.args.area, inst.args.invert, false);
+	let keys = query_keys(&mut inst.db, &inst.status,
+		&[], inst.args.area, inst.args.invert, false);
 	inst.status.begin_editing();
 
 	for key in keys {
diff --git a/src/commands/delete_meta.rs b/src/commands/delete_meta.rs
index 815f89c..c15b687 100644
--- a/src/commands/delete_meta.rs
+++ b/src/commands/delete_meta.rs
@@ -4,14 +4,14 @@ use crate::unwrap_or;
 use crate::spatial::Vec3;
 use crate::instance::{ArgType, InstBundle};
 use crate::map_block::{MapBlock, NodeMetadataList};
-use crate::utils::{query_keys, fmt_big_num};
+use crate::utils::{query_keys, to_bytes, to_slice, fmt_big_num};
 
 
 fn delete_metadata(inst: &mut InstBundle) {
-	let node = inst.args.node.as_ref().map(|s| s.as_bytes().to_owned());
+	let node = inst.args.node.as_ref().map(to_bytes);
 
 	let keys = query_keys(&mut inst.db, &mut inst.status,
-		node.iter().collect(), inst.args.area, inst.args.invert, true);
+		&to_slice(&node), inst.args.area, inst.args.invert, true);
 
 	inst.status.begin_editing();
 	let mut count: u64 = 0;
diff --git a/src/commands/delete_objects.rs b/src/commands/delete_objects.rs
index f7ed059..ef74c27 100644
--- a/src/commands/delete_objects.rs
+++ b/src/commands/delete_objects.rs
@@ -4,7 +4,7 @@ use crate::unwrap_or;
 use crate::spatial::Area;
 use crate::instance::{ArgType, InstBundle};
 use crate::map_block::{MapBlock, StaticObject, LuaEntityData};
-use crate::utils::{query_keys, fmt_big_num};
+use crate::utils::{query_keys, to_bytes, to_slice, fmt_big_num};
 
 use memmem::{Searcher, TwoWaySearcher};
 
@@ -54,19 +54,18 @@ fn delete_objects(inst: &mut InstBundle) {
 	let search_obj = if inst.args.items.is_some() {
 		Some(ITEM_ENT_NAME.to_owned())
 	} else {
-		inst.args.object.as_ref().map(|s| s.as_bytes().to_owned())
+		inst.args.object.as_ref().map(to_bytes)
 	};
 
 	// search_item will be Some if (1) item search is enabled and (2) an item
 	// is specified.
-	let search_item = inst.args.items.as_ref()
-		.and_then(|items| items.get(0))
-		.map(|s| s.as_bytes().to_owned());
+	let search_item = inst.args.items.as_ref().and_then(|items| items.get(0))
+		.map(to_bytes);
 	let item_searcher = search_item.as_ref()
 		.map(|s| TwoWaySearcher::new(s));
 
 	let keys = query_keys(&mut inst.db, &mut inst.status,
-		search_obj.iter().collect(), inst.args.area, inst.args.invert, true);
+		&to_slice(&search_obj), inst.args.area, inst.args.invert, true);
 
 	inst.status.begin_editing();
 	let mut count: u64 = 0;
diff --git a/src/commands/delete_timers.rs b/src/commands/delete_timers.rs
index a9aa5d5..319c1ac 100644
--- a/src/commands/delete_timers.rs
+++ b/src/commands/delete_timers.rs
@@ -4,14 +4,14 @@ use crate::unwrap_or;
 use crate::spatial::Vec3;
 use crate::instance::{ArgType, InstBundle};
 use crate::map_block::MapBlock;
-use crate::utils::{query_keys, fmt_big_num};
+use crate::utils::{query_keys, to_bytes, to_slice, fmt_big_num};
 
 
 fn delete_timers(inst: &mut InstBundle) {
-	let node = inst.args.node.as_ref().map(|s| s.as_bytes().to_owned());
+	let node = inst.args.node.as_ref().map(to_bytes);
 
 	let keys = query_keys(&mut inst.db, &mut inst.status,
-		node.iter().collect(), inst.args.area, inst.args.invert, true);
+		&to_slice(&node), inst.args.area, inst.args.invert, true);
 
 	inst.status.begin_editing();
 	let mut count: u64 = 0;
diff --git a/src/commands/fill.rs b/src/commands/fill.rs
index 07d3837..da8f0e0 100644
--- a/src/commands/fill.rs
+++ b/src/commands/fill.rs
@@ -4,7 +4,7 @@ use crate::spatial::{Vec3, Area, area_rel_block_overlap, area_contains_block};
 use crate::instance::{ArgType, InstBundle};
 use crate::map_block::{MapBlock};
 use crate::block_utils::clean_name_id_map;
-use crate::utils::{query_keys, fmt_big_num};
+use crate::utils::{query_keys, to_bytes, fmt_big_num};
 
 
 fn fill_area(block: &mut MapBlock, area: Area, id: u16) {
@@ -23,10 +23,10 @@ fn fill_area(block: &mut MapBlock, area: Area, id: u16) {
 
 fn fill(inst: &mut InstBundle) {
 	let area = inst.args.area.unwrap();
-	let node = inst.args.new_node.as_ref().unwrap().as_bytes().to_owned();
+	let node = to_bytes(inst.args.new_node.as_ref().unwrap());
 
 	let keys = query_keys(&mut inst.db, &mut inst.status,
-		Vec::new(), Some(area), false, true);
+		&[], Some(area), false, true);
 
 	inst.status.begin_editing();
 
diff --git a/src/commands/overlay.rs b/src/commands/overlay.rs
index 5b73957..838f787 100644
--- a/src/commands/overlay.rs
+++ b/src/commands/overlay.rs
@@ -31,7 +31,7 @@ fn overlay_no_offset(inst: &mut InstBundle) {
 
 	// Get keys from input database.
 	let keys = query_keys(&mut idb, &inst.status,
-		Vec::new(), inst.args.area, invert, true);
+		&[], inst.args.area, invert, true);
 	inst.status.begin_editing();
 
 	for key in keys {
@@ -107,7 +107,7 @@ fn overlay_with_offset(inst: &mut InstBundle) {
 
 	// Get keys from output database.
 	let keys = query_keys(&mut inst.db, &inst.status,
-		Vec::new(), dst_area, inst.args.invert, true);
+		&[], dst_area, inst.args.invert, true);
 	inst.status.begin_editing();
 
 	for key in keys {
diff --git a/src/commands/replace_in_inv.rs b/src/commands/replace_in_inv.rs
index 0f875b8..dd3b2fb 100644
--- a/src/commands/replace_in_inv.rs
+++ b/src/commands/replace_in_inv.rs
@@ -4,7 +4,7 @@ use crate::unwrap_or;
 use crate::spatial::Vec3;
 use crate::instance::{ArgType, InstBundle};
 use crate::map_block::{MapBlock, NodeMetadataList};
-use crate::utils::{query_keys, fmt_big_num};
+use crate::utils::{query_keys, to_bytes, fmt_big_num};
 
 const NEWLINE: u8 = b'\n';
 const SPACE: u8 = b' ';
@@ -18,8 +18,12 @@ fn do_replace(inv: &mut Vec<u8>, item: &[u8], new_item: &[u8], del_meta: bool)
 	let mut mods = 0;
 
 	for line in inv.split(|&x| x == NEWLINE) {
-		let mut parts = line.splitn(4, |&x| x == SPACE);
+		if line.is_empty() {
+			// Necessary because of newline after final EndInventory
+			continue;
+		}
 
+		let mut parts = line.splitn(4, |&x| x == SPACE);
 		if parts.next() == Some(b"Item") && parts.next() == Some(item) {
 			if delete {
 				new_inv.extend_from_slice(b"Empty");
@@ -53,13 +57,13 @@ fn do_replace(inv: &mut Vec<u8>, item: &[u8], new_item: &[u8], del_meta: bool)
 
 
 fn replace_in_inv(inst: &mut InstBundle) {
-	let item = inst.args.item.as_ref().unwrap().as_bytes().to_owned();
-	let new_item = inst.args.new_item.as_ref().unwrap().as_bytes().to_owned();
+	let item = to_bytes(inst.args.item.as_ref().unwrap());
+	let new_item = to_bytes(inst.args.new_item.as_ref().unwrap());
 	let del_meta = false;
-	let node = inst.args.node.as_ref().map(|s| s.as_bytes().to_owned());
+	let nodes: Vec<_> = inst.args.nodes.iter().map(to_bytes).collect();
 
 	let keys = query_keys(&mut inst.db, &mut inst.status,
-		node.iter().collect(), inst.args.area, inst.args.invert, true);
+		&nodes, inst.args.area, inst.args.invert, true);
 
 	inst.status.begin_editing();
 	let mut item_mods: u64 = 0;
@@ -71,9 +75,10 @@ fn replace_in_inv(inst: &mut InstBundle) {
 		let mut block = unwrap_or!(MapBlock::deserialize(&data), continue);
 
 		let node_data = block.node_data.get_ref();
-		let node_id = node.as_deref().and_then(|n| block.nimap.get_id(n));
-		if node.is_some() && node_id.is_none() {
-			continue; // Block doesn't contain the required node.
+		let node_ids: Vec<_> = nodes.iter()
+			.filter_map(|n| block.nimap.get_id(n)).collect();
+		if !nodes.is_empty() && node_ids.is_empty() {
+			continue; // Block doesn't contain any of the required nodes.
 		}
 
 		let mut meta = unwrap_or!(
@@ -90,10 +95,10 @@ fn replace_in_inv(inst: &mut InstBundle) {
 					continue;
 				}
 			}
-			if let Some(id) = node_id {
-				if node_data.nodes[idx as usize] != id {
-					continue;
-				}
+			if !node_ids.is_empty()
+				&& !node_ids.contains(&node_data.nodes[idx as usize])
+			{
+				continue;
 			}
 
 			let i_mods = do_replace(&mut data.inv, &item, &new_item, del_meta);
@@ -125,7 +130,7 @@ pub fn get_command() -> Command {
 			(ArgType::NewItem, "Name of new item to replace with"),
 			(ArgType::Area(false), "Area in which to modify inventories"),
 			(ArgType::Invert, "Modify inventories outside the given area."),
-			(ArgType::Node(false), "Node to modify inventories of")
+			(ArgType::Nodes, "Names of nodes to modify inventories of")
 		],
 		help: "Replace items in node inventories."
 	}
diff --git a/src/commands/replace_nodes.rs b/src/commands/replace_nodes.rs
index db04f4c..d895685 100644
--- a/src/commands/replace_nodes.rs
+++ b/src/commands/replace_nodes.rs
@@ -4,9 +4,8 @@ use crate::spatial::{Vec3, Area, area_contains_block, area_touches_block,
 	area_rel_block_overlap};
 use crate::instance::{ArgType, InstArgs, InstBundle};
 use crate::map_block::MapBlock;
-use crate::utils::query_keys;
 use crate::time_keeper::TimeKeeper;
-use crate::utils::fmt_big_num;
+use crate::utils::{query_keys, to_bytes, fmt_big_num};
 
 
 fn do_replace(
@@ -113,10 +112,10 @@ fn do_replace(
 
 
 fn replace_nodes(inst: &mut InstBundle) {
-	let node = inst.args.node.as_ref().unwrap().as_bytes().to_owned();
-	let new_node = inst.args.new_node.as_ref().unwrap().as_bytes().to_owned();
+	let node = to_bytes(inst.args.node.as_ref().unwrap());
+	let new_node = to_bytes(inst.args.new_node.as_ref().unwrap());
 	let keys = query_keys(&mut inst.db, &inst.status,
-		vec![&node], inst.args.area, inst.args.invert, true);
+		std::slice::from_ref(&node), inst.args.area, inst.args.invert, true);
 
 	inst.status.begin_editing();
 	let mut count = 0;
diff --git a/src/commands/set_meta_var.rs b/src/commands/set_meta_var.rs
index 5069113..c2543e8 100644
--- a/src/commands/set_meta_var.rs
+++ b/src/commands/set_meta_var.rs
@@ -4,16 +4,16 @@ use crate::unwrap_or;
 use crate::spatial::Vec3;
 use crate::instance::{ArgType, InstBundle};
 use crate::map_block::{MapBlock, NodeMetadataList};
-use crate::utils::{query_keys, fmt_big_num};
+use crate::utils::{query_keys, to_bytes, fmt_big_num};
 
 
 fn set_meta_var(inst: &mut InstBundle) {
-	let key = inst.args.key.as_ref().unwrap().as_bytes().to_owned();
-	let value = inst.args.value.as_ref().unwrap().as_bytes().to_owned();
-	let node = inst.args.node.as_ref().map(|s| s.as_bytes().to_owned());
+	let key = to_bytes(inst.args.key.as_ref().unwrap());
+	let value = to_bytes(inst.args.value.as_ref().unwrap());
+	let nodes: Vec<_> = inst.args.nodes.iter().map(to_bytes).collect();
 
 	let keys = query_keys(&mut inst.db, &mut inst.status,
-		node.iter().collect(), inst.args.area, inst.args.invert, true);
+		&nodes, inst.args.area, inst.args.invert, true);
 
 	inst.status.begin_editing();
 	let mut count: u64 = 0;
@@ -24,9 +24,10 @@ fn set_meta_var(inst: &mut InstBundle) {
 		let mut block = unwrap_or!(MapBlock::deserialize(&data), continue);
 
 		let node_data = block.node_data.get_ref();
-		let node_id = node.as_deref().and_then(|n| block.nimap.get_id(n));
-		if node.is_some() && node_id.is_none() {
-			continue; // Block doesn't contain the required node.
+		let node_ids: Vec<_> = nodes.iter()
+			.filter_map(|n| block.nimap.get_id(n)).collect();
+		if !nodes.is_empty() && node_ids.is_empty() {
+			continue; // Block doesn't contain any of the required nodes.
 		}
 
 		let mut meta = unwrap_or!(
@@ -44,10 +45,10 @@ fn set_meta_var(inst: &mut InstBundle) {
 					continue;
 				}
 			}
-			if let Some(id) = node_id {
-				if node_data.nodes[idx as usize] != id {
-					continue;
-				}
+			if !node_ids.is_empty()
+				&& !node_ids.contains(&node_data.nodes[idx as usize])
+			{
+				continue;
 			}
 
 			if let Some(val) = data.vars.get_mut(&key) {
@@ -76,11 +77,12 @@ pub fn get_command() -> Command {
 		args: vec![
 			(ArgType::Key, "Name of key to set in metadata"),
 			(ArgType::Value, "Value to set in metadata"),
-			(ArgType::Area(false), "Area in which to modify node metadata"),
+			(ArgType::Area(false),
+				"Optional area in which to modify node metadata"),
 			(ArgType::Invert, "Modify node metadata outside the given area."),
-			(ArgType::Node(false),
-				"Node to modify metadata in. If not specified, all relevant \
-				metadata will be modified.")
+			(ArgType::Nodes,
+				"Names of one or more nodes to modify. If not specified, all \
+				nodes with the specified variable will be modified.")
 		],
 		help: "Set a variable in node metadata."
 	}
diff --git a/src/commands/set_param2.rs b/src/commands/set_param2.rs
index 2164447..79ee8b5 100644
--- a/src/commands/set_param2.rs
+++ b/src/commands/set_param2.rs
@@ -3,7 +3,7 @@ use super::Command;
 use crate::spatial::{Vec3, Area, area_rel_block_overlap, area_contains_block};
 use crate::instance::{ArgType, InstArgs, InstBundle};
 use crate::map_block::{MapBlock};
-use crate::utils::{query_keys, fmt_big_num};
+use crate::utils::{query_keys, to_bytes, to_slice, fmt_big_num};
 
 
 fn set_in_area_node(block: &mut MapBlock, area: Area, id: u16, val: u8) -> u64
@@ -43,10 +43,10 @@ fn set_in_area(block: &mut MapBlock, area: Area, val: u8) {
 
 fn set_param2(inst: &mut InstBundle) {
 	let param2_val = inst.args.param2_val.unwrap();
-	let node = inst.args.node.as_ref().map(|s| s.as_bytes().to_owned());
+	let node = inst.args.node.as_ref().map(to_bytes);
 
 	let keys = query_keys(&mut inst.db, &mut inst.status,
-		node.iter().collect(), inst.args.area, false, true);
+		to_slice(&node), inst.args.area, false, true);
 
 	inst.status.begin_editing();
 
diff --git a/src/instance.rs b/src/instance.rs
index 2e6a80e..c62ea40 100644
--- a/src/instance.rs
+++ b/src/instance.rs
@@ -16,6 +16,7 @@ pub enum ArgType {
 	Invert,
 	Offset(bool),
 	Node(bool),
+	Nodes,
 	NewNode,
 	Item,
 	NewItem,
@@ -36,6 +37,7 @@ pub struct InstArgs {
 	pub invert: bool,
 	pub offset: Option<Vec3>,
 	pub node: Option<String>,
+	pub nodes: Vec<String>,
 	pub new_node: Option<String>,
 	pub item: Option<String>,
 	pub new_item: Option<String>,
diff --git a/src/utils.rs b/src/utils.rs
index 574ccd9..43c3f64 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -11,8 +11,7 @@ use crate::spatial::{Area, Vec3};
 pub fn query_keys(
 	db: &mut MapDatabase,
 	status: &StatusServer,
-	// TODO: Allow multiple names for setmetavar and replaceininv.
-	search_strs: Vec<&Vec<u8>>,
+	search_strs: &[Vec<u8>],
 	area: Option<Area>,
 	invert: bool,
 	include_partial: bool
@@ -21,7 +20,7 @@ pub fn query_keys(
 
 	// Prepend 16-bit search string length to reduce false positives.
 	// This will break if the name-ID map format changes.
-	let string16s: Vec<Vec<u8>> = search_strs.iter().map(|&s| {
+	let string16s: Vec<Vec<u8>> = search_strs.iter().map(|s| {
 		let mut res = Vec::new();
 		res.write_u16::<BigEndian>(s.len() as u16).unwrap();
 		res.extend(s);
@@ -49,11 +48,10 @@ pub fn query_keys(
 				continue;
 			}
 		}
-		if !data_searchers.is_empty() {
-			// Data must match at least one search string.
-			if data_searchers.iter().any(|s| s.search_in(&data).is_some()) {
-				continue;
-			}
+		if !data_searchers.is_empty()
+			&& !data_searchers.iter().any(|s| s.search_in(&data).is_some())
+		{ // Data must match at least one search string.
+			continue;
 		}
 		keys.push(key);
 
@@ -69,6 +67,19 @@ pub fn query_keys(
 }
 
 
+pub fn to_bytes(s: &String) -> Vec<u8> {
+	s.as_bytes().to_vec()
+}
+
+
+pub fn to_slice(opt: &Option<Vec<u8>>) -> &[Vec<u8>] {
+	match opt {
+		Some(x) => std::slice::from_ref(x),
+		None => &[]
+	}
+}
+
+
 #[macro_export]
 macro_rules! unwrap_or {
 	($res:expr, $alt:expr) => {