# LibTmux::Server#list_windows

- **Module:** LibTmux
- **Package:** libtmux
- **Language:** Ruby
- **Kind:** method
- **Source:** https://github.com/libtmux/libtmux-ruby/blob/da7b6191b9439e3c84fa1c9eeaa9168263ee7af4/gems/libtmux/lib/libtmux/server.rb#L270
- **Page:** https://libtmux.org/en/ruby/v0.1.1/reference/libtmux-server-list_windows/

```
def list_windows: (
  ?timeout: ::Numeric,
  ?cancel: untyped
) -> ::Array[::LibTmux::Window]
```

Behavior: Live acquisition.

Behavior contract: Live acquisition.

## Examples

List all server windows and the windows belonging to one session. Use Ruby 3.3 or newer with Bundler, and tmux 3.3a or newer, on Unix with `/bin/cat` and `/bin/sh` available. In an empty directory, save this `Gemfile`:

```ruby
source "https://rubygems.org"

gem "libtmux", "0.1.1"
```

Save this complete program as `list_windows.rb`. Its `Server.start` block owns a private tmux server and stops it on exit, including after an error.

[Source example](https://github.com/libtmux/libtmux-ruby/blob/da7b6191b9439e3c84fa1c9eeaa9168263ee7af4/examples/api/list_windows.rb).

```ruby
# frozen_string_literal: true

require "libtmux"

begin
  LibTmux::Server.start do |server|
    work = server.new_session(name: "work", command: ["/bin/cat"])
    work.new_window(name: "logs", command: ["/bin/cat"])
    server.new_session(name: "other", command: ["/bin/cat"])
    puts "server windows: #{server.list_windows.length}"
    puts "work windows: #{work.list_windows.length}"
  end
rescue StandardError => error
  warn "#{error.class}: #{error.message}"
  exit 1
end
```

Install the gem and run the program. An operation or cleanup error makes it exit unsuccessfully:

```console
$ bundle install && \
  bundle exec ruby list_windows.rb
```

Expected output:

```text
server windows: 3
work windows: 2
```

## Parameters

- `timeout` (`::Numeric`)
- `cancel` (`untyped`)

## tmux command

The tmux commands behind `list_windows`.

- [`list-windows`](/en/tmux/latest/manual/list-windows/) `-a` server scope, [`cmd_list_windows_exec`](/en/tmux/latest/reference/c-function-cmd-list-windows-c-cmd_list_windows_exec/) (source: `gems/libtmux/lib/libtmux/server.rb:470`)

## tmux C API

The C declarations in tmux that implement these commands.

- [`cmd_list_windows_entry`](/en/tmux/latest/reference/c-variable-cmd_list_windows_entry/) (attribute)
- [`cmd_list_windows_exec`](/en/tmux/latest/reference/c-function-cmd-list-windows-c-cmd_list_windows_exec/) (function)

## In other ports

List the server's windows

| Language | Equivalent |
| --- | --- |
| Python | [`libtmux.Server.windows`](/en/py/latest/reference/libtmux-server-windows/) (property) |
| Lua | [`libtmux.Snapshot.windows`](/en/lua/latest/reference/libtmux-snapshot-windows/) (attribute) |
| PowerShell | [`LibTmux\Get-TmuxWindow`](/en/powershell/latest/reference/libtmux-get-tmuxwindow/) (cmdlet). Use the [`-Server`](/en/powershell/latest/reference/libtmux-get-tmuxwindow/#LibTmux%5CGet-TmuxWindow.parameter.Server) parameter set to acquire window placements across all sessions. |
| Julia | [`LibTmux.windows`](/en/julia/latest/reference/libtmux-windows/) (function). `windows` with a `Snapshot` reads every captured physical window. Use `windowlinks` for session placements. |
| Elixir | [`LibTmux.Snapshot.windows/1`](/en/elixir/latest/reference/libtmux-snapshot-windows-1/) (function). Returns a `Selection` of every captured physical window. `window_links/1` lists session placements. |
| TypeScript | [`server.Server.windows`](/en/ts/latest/reference/server-server-windows/) (method) |
| Rust | [`server.Server.windows`](/en/rs/latest/reference/server-server-windows/) (method) |
| Go | [`tmux.Server.Windows`](/en/go/latest/reference/tmux-server-windows/) (method) |
| Java | [`io.github.libtmux.Server.windows`](/en/java/latest/reference/io-github-libtmux-server-server-windows/) (method) |
| Kotlin | [`io.github.libtmux.kotlin.Server.windows`](/en/kotlin/latest/reference/io-github-libtmux-kotlin-server-windows/) (method) |
| Scala | [`io.github.libtmux.scaladsl.Server.windows`](/en/scala/latest/reference/io-github-libtmux-scaladsl-server-windows/) (method) |
| C# | [`LibTmux.Server.Windows`](/en/csharp/latest/reference/libtmux-server-windows/) (property) |
| F# | [`LibTmux.FSharp.Server.windows`](/en/fsharp/latest/reference/libtmux-fsharp-server-windows/) (function). Builds a deferred query for placements across all sessions. `Query.list` acquires the results; a linked window appears once for each session placement. |
| C++ | [`libtmux::Server::windows`](/en/cxx/latest/reference/libtmux-server-windows/) (method) |
| Swift | [`Server.windows()`](/en/swift/latest/reference/server-windows()/) (method) |