diff --git a/build.zig b/build.zig
index 8d3c126..3168c03 100644
--- a/build.zig
+++ b/build.zig
@@ -392,6 +392,13 @@ pub fn build_exe(
         },
     });
 
+    const argv_mod = b.createModule(.{
+        .root_source_file = b.path("src/argv.zig"),
+        .imports = &.{
+            .{ .name = "cbor", .module = cbor_mod },
+        },
+    });
+
     const lsp_config_mod = b.createModule(.{
         .root_source_file = b.path("src/lsp_config.zig"),
         .imports = &.{
@@ -660,6 +667,7 @@ pub fn build_exe(
             .{ .name = "project_manager", .module = project_manager_mod },
             .{ .name = "syntax", .module = syntax_mod },
             .{ .name = "text_manip", .module = text_manip_mod },
+            .{ .name = "argv", .module = argv_mod },
             .{ .name = "Buffer", .module = Buffer_mod },
             .{ .name = "keybind", .module = keybind_mod },
             .{ .name = "shell", .module = shell_mod },
@@ -709,6 +717,7 @@ pub fn build_exe(
     exe.root_module.addImport("cbor", cbor_mod);
     exe.root_module.addImport("config", config_mod);
     exe.root_module.addImport("text_manip", text_manip_mod);
+    exe.root_module.addImport("argv", argv_mod);
     exe.root_module.addImport("Buffer", Buffer_mod);
     exe.root_module.addImport("tui", tui_mod);
     exe.root_module.addImport("thespian", thespian_mod);
@@ -759,6 +768,7 @@ pub fn build_exe(
     check_exe.root_module.addImport("cbor", cbor_mod);
     check_exe.root_module.addImport("config", config_mod);
     check_exe.root_module.addImport("text_manip", text_manip_mod);
+    check_exe.root_module.addImport("argv", argv_mod);
     check_exe.root_module.addImport("Buffer", Buffer_mod);
     check_exe.root_module.addImport("tui", tui_mod);
     check_exe.root_module.addImport("thespian", thespian_mod);
diff --git a/src/argv.zig b/src/argv.zig
new file mode 100644
index 0000000..3e6d5ec
--- /dev/null
+++ b/src/argv.zig
@@ -0,0 +1,33 @@
+const std = @import("std");
+
+/// Write a `[]const []const u8` argv array as a space-separated command string.
+/// Args that contain spaces are wrapped in double-quotes.
+/// Writes nothing if argv is null or empty.
+pub fn write(writer: *std.Io.Writer, argv: ?[]const []const u8) error{WriteFailed}!usize {
+    const args = argv orelse return 0;
+    var count: usize = 0;
+    for (args, 0..) |arg, i| {
+        if (i > 0) {
+            try writer.writeByte(' ');
+            count += 1;
+        }
+        const needs_quote = std.mem.indexOfScalar(u8, arg, ' ') != null;
+        if (needs_quote) {
+            try writer.writeByte('"');
+            count += 1;
+        }
+        try writer.writeAll(arg);
+        count += arg.len;
+        if (needs_quote) {
+            try writer.writeByte('"');
+            count += 1;
+        }
+    }
+    return count;
+}
+
+/// Return the display length of an argv array rendered by write_argv.
+pub fn len(argv: ?[]const []const u8) usize {
+    var discard: std.Io.Writer.Discarding = .init(&.{});
+    return write(&discard.writer, argv) catch return 0;
+}
diff --git a/src/list_languages.zig b/src/list_languages.zig
index 8296e87..669c786 100644
--- a/src/list_languages.zig
+++ b/src/list_languages.zig
@@ -3,6 +3,7 @@ const file_type_config = @import("file_type_config");
 const text_manip = @import("text_manip");
 const write_string = text_manip.write_string;
 const write_padding = text_manip.write_padding;
+const argv = @import("argv");
 const builtin = @import("builtin");
 const RGB = @import("color").RGB;
 
@@ -22,9 +23,9 @@ pub fn list(allocator: std.mem.Allocator, writer: *std.io.Writer, tty_config: st
     for (file_type_config.get_all_names()) |file_type_name| {
         const file_type = try file_type_config.get(file_type_name) orelse unreachable;
         max_language_len = @max(max_language_len, file_type.name.len);
-        max_langserver_len = @max(max_langserver_len, args_string_length(file_type.language_server));
-        max_formatter_len = @max(max_formatter_len, args_string_length(file_type.formatter));
-        max_extensions_len = @max(max_extensions_len, args_string_length(file_type.extensions));
+        max_langserver_len = @max(max_langserver_len, argv.len(file_type.language_server));
+        max_formatter_len = @max(max_formatter_len, argv.len(file_type.formatter));
+        max_extensions_len = @max(max_extensions_len, argv.len(file_type.extensions));
     }
 
     try tty_config.setColor(writer, .yellow);
@@ -43,59 +44,42 @@ pub fn list(allocator: std.mem.Allocator, writer: *std.io.Writer, tty_config: st
         try tty_config.setColor(writer, .reset);
         try writer.writeAll("  ");
         try write_string(writer, file_type.name, max_language_len + 1);
-        try write_segmented(writer, file_type.extensions, ",", max_extensions_len + 1, tty_config);
+        {
+            const exts = file_type.extensions orelse &.{};
+            var ext_len: usize = 0;
+            for (exts, 0..) |ext, i| {
+                if (i > 0) {
+                    try writer.writeByte(',');
+                    ext_len += 1;
+                }
+                try writer.writeAll(ext);
+                ext_len += ext.len;
+            }
+            try tty_config.setColor(writer, .reset);
+            try write_padding(writer, ext_len, max_extensions_len + 1);
+        }
 
         if (file_type.language_server) |language_server|
             try write_checkmark(writer, bin_path.can_execute(allocator, language_server[0]), tty_config);
 
-        try write_segmented(writer, file_type.language_server, " ", max_langserver_len + 1, tty_config);
+        const len = try argv.write(writer, file_type.language_server);
+        try tty_config.setColor(writer, .reset);
+        try write_padding(writer, len, max_langserver_len + 1);
 
         if (file_type.formatter) |formatter|
             try write_checkmark(writer, bin_path.can_execute(allocator, formatter[0]), tty_config);
 
-        try write_segmented(writer, file_type.formatter, " ", null, tty_config);
+        _ = try argv.write(writer, file_type.formatter);
+        try tty_config.setColor(writer, .reset);
         try writer.writeAll("\n");
     }
 }
 
-fn args_string_length(args_: ?[]const []const u8) usize {
-    const args = args_ orelse return 0;
-    var len: usize = 0;
-    var first: bool = true;
-    for (args) |arg| {
-        if (first) first = false else len += 1;
-        len += arg.len;
-    }
-    return len;
-}
-
 fn write_checkmark(writer: anytype, success: bool, tty_config: std.io.tty.Config) !void {
     try tty_config.setColor(writer, if (success) .green else .red);
     if (success) try writer.writeAll(success_mark) else try writer.writeAll(fail_mark);
 }
 
-fn write_segmented(
-    writer: anytype,
-    args_: ?[]const []const u8,
-    sep: []const u8,
-    pad: ?usize,
-    tty_config: std.io.tty.Config,
-) !void {
-    const args = args_ orelse return;
-    var len: usize = 0;
-    var first: bool = true;
-    for (args) |arg| {
-        if (first) first = false else {
-            len += 1;
-            try writer.writeAll(sep);
-        }
-        len += arg.len;
-        try writer.writeAll(arg);
-    }
-    try tty_config.setColor(writer, .reset);
-    if (pad) |pad_| try write_padding(writer, len, pad_);
-}
-
 fn setColorRgb(writer: anytype, color: u24) !void {
     const fg_rgb_legacy = "\x1b[38;2;{d};{d};{d}m";
     const rgb = RGB.from_u24(color);
diff --git a/src/tui/terminal_view.zig b/src/tui/terminal_view.zig
index 44ebe0d..0eb6c1d 100644
--- a/src/tui/terminal_view.zig
+++ b/src/tui/terminal_view.zig
@@ -6,6 +6,7 @@ const cbor = @import("cbor");
 const command = @import("command");
 const vaxis = @import("renderer").vaxis;
 const shell = @import("shell");
+const argv = @import("argv");
 
 const Plane = @import("renderer").Plane;
 const Widget = @import("Widget.zig");
@@ -274,18 +275,11 @@ fn show_exit_message(self: *Self, code: u8) void {
     if (code != 0)
         w.print(" with code {d}", .{code}) catch {};
     w.writeAll("]\x1b[0m\r\n") catch {};
-    // Build display command string from argv for the re-run prompt
-    const argv = self.vt.vt.cmd.argv;
-    if (argv.len > 0) {
+    // Re-run prompt
+    const cmd_argv = self.vt.vt.cmd.argv;
+    if (cmd_argv.len > 0) {
         w.writeAll("\x1b[0m\x1b[2mPress enter to re-run '") catch {};
-        for (argv, 0..) |arg, i| {
-            if (i > 0) w.writeByte(' ') catch {};
-            // Quote args that contain spaces
-            const needs_quote = std.mem.indexOfScalar(u8, arg, ' ') != null;
-            if (needs_quote) w.writeByte('"') catch {};
-            w.writeAll(arg) catch {};
-            if (needs_quote) w.writeByte('"') catch {};
-        }
+        _ = argv.write(w, cmd_argv) catch {};
         w.writeAll("'\x1b[0m\r\n") catch {};
     }
     var parser: pty.Parser = .{ .buf = .init(self.allocator) };
@@ -355,7 +349,7 @@ const Vt = struct {
     app_cursor: ?[3]u8 = null,
     process_exited: bool = false,
 
-    fn init(allocator: std.mem.Allocator, argv: []const []const u8, env: std.process.EnvMap, rows: u16, cols: u16) !void {
+    fn init(allocator: std.mem.Allocator, cmd_argv: []const []const u8, env: std.process.EnvMap, rows: u16, cols: u16) !void {
         const home = env.get("HOME") orelse "/tmp";
 
         global_vt = .{
@@ -367,7 +361,7 @@ const Vt = struct {
         const self = &global_vt.?;
         self.vt = try Terminal.init(
             allocator,
-            argv,
+            cmd_argv,
             &env,
             .{
                 .winsize = .{ .rows = rows, .cols = cols, .x_pixel = 0, .y_pixel = 0 },