# LibTmux::Server#snapshot

- **Module:** LibTmux
- **Package:** libtmux
- **Language:** Ruby
- **Kind:** method
- **Source:** https://github.com/libtmux/libtmux-ruby/blob/c8b839595d5a30e271e3f9be0d0fe811ddb11b7e/gems/libtmux/lib/libtmux/server.rb#L334
- **Page:** https://libtmux.org/en/ruby/v0.1.0/reference/libtmux-server-snapshot/

tmux command: [`list-clients`](/en/tmux/latest/manual/list-clients/)

tmux command: [`list-panes`](/en/tmux/latest/manual/list-panes/) server scope, [`cmd_list_panes_server`](/en/tmux/latest/reference/c-function-cmd-list-panes-c-cmd_list_panes_server/)

tmux command: [`list-sessions`](/en/tmux/latest/manual/list-sessions/)

tmux command: [`list-windows`](/en/tmux/latest/manual/list-windows/) server scope, [`cmd_list_windows_exec`](/en/tmux/latest/reference/c-function-cmd-list-windows-c-cmd_list_windows_exec/)

```
def snapshot: (
  ?timeout: ::Numeric,
  ?cancel: untyped,
  ?clients: bool,
  ?max_bytes: ::Integer,
  ?max_rows: ::Integer,
  ?max_field_bytes: ::Integer
) -> ::LibTmux::Snapshot
```

Behavior: Snapshot acquisition.

Behavior contract: Snapshot acquisition.

## Examples

Filter a captured snapshot, distinguish a missing session, and acquire a fresh pane selection. one raises unless exactly one record matches; one_or_nil returns nil only for zero matches. Use Ruby 4.0.7, Bundler, Git and tmux 3.3a or newer on Unix, with /bin/cat and /bin/sh available. In an empty directory, fetch the documented library revision:

```console
$ git clone https://github.com/libtmux/libtmux-ruby.git libtmux-source && \
  git -C libtmux-source checkout c8b839595d5a30e271e3f9be0d0fe811ddb11b7e
```

Save this dependency file as Gemfile:

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

gem "libtmux", path: "libtmux-source/gems/libtmux"
```

Save this complete program as query.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/c8b839595d5a30e271e3f9be0d0fe811ddb11b7e/examples/api/query.rb).

```ruby
# frozen_string_literal: true

begin
  # docs:begin main
  require "libtmux"

  LibTmux::Server.start do |server|
    work = server.new_session(name: "work", command: ["/bin/cat"], receipt: true)
    server.new_session(name: "logs", command: ["/bin/cat"])
    snapshot = server.snapshot
    session = snapshot.sessions.where(name: "work").one
    puts "matching session: #{session.name}"
    missing = snapshot.sessions.one_or_nil(name: "missing")
    puts "missing session: #{missing.nil?}"
    panes = server.search_panes(where: {id: work.pane.id})
    puts "matching pane: #{panes.one.id}"
  end
  # docs:end main
rescue StandardError => error
  warn "#{error.class}: #{error.message}"
  exit 1
end
```

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

```console
$ bundle config set --local path vendor/bundle && \
  bundle install --jobs 2 && \
  bundle exec ruby query.rb
```

Expected output:

```text
matching session: work
missing session: true
matching pane: %0
```

## Parameters

- `timeout` (`::Numeric`)
- `cancel` (`untyped`)
- `clients` (`bool`)
- `max_bytes` (`::Integer`)
- `max_rows` (`::Integer`)
- `max_field_bytes` (`::Integer`)

## In other ports

### Capture the tmux hierarchy

- PowerShell: [`LibTmux\Get-TmuxSnapshot`](/en/powershell/latest/reference/libtmux-get-tmuxsnapshot/) (cmdlet). Acquires a replacement `LibTmux.Server` to [`-Depth`](/en/powershell/latest/reference/libtmux-get-tmuxsnapshot/#LibTmux%5CGet-TmuxSnapshot.parameter.Depth) (panes by default). Acquisition is not atomic; retained handles do not refresh.
- Julia: [`LibTmux.snapshot`](/en/julia/latest/reference/libtmux-snapshot-1gv6/) (function). Acquires a new `Snapshot` over an observation interval. Topology checks do not make it a transaction; earlier snapshots do not refresh.
- Elixir: [`LibTmux.Server.snapshot/2`](/en/elixir/latest/reference/libtmux-server-snapshot-2/) (function). Captures a new graph over an observation interval. A retained `Snapshot` never refreshes.
- Lua: [`libtmux.Server:snapshot`](/en/lua/latest/reference/libtmux-server-snapshot/) (method)
- TypeScript: [`server.Server.snapshot`](/en/ts/latest/reference/server-server-snapshot/) (method)
- Go: [`tmux.Server.Snapshot`](/en/go/latest/reference/tmux-server-snapshot/) (method)
- Java: [`io.github.libtmux.Server.Server.snapshot`](/en/java/latest/reference/io-github-libtmux-server-server-snapshot/) (method)
- C#: [`LibTmux.Server.CaptureSnapshotAsync`](/en/csharp/latest/reference/libtmux-server-capturesnapshotasync/) (method)
- Swift: [`Server.snapshot()`](/en/swift/latest/reference/server-snapshot()/) (method)
- Kotlin: [`io.github.libtmux.kotlin.Server.snapshot`](/en/kotlin/latest/reference/io-github-libtmux-kotlin-server-snapshot/) (method)
- Scala: [`io.github.libtmux.scaladsl.Server.snapshot`](/en/scala/latest/reference/io-github-libtmux-scaladsl-server-snapshot/) (method)
- F#: [`LibTmux.FSharp.Server.capture`](/en/fsharp/latest/reference/libtmux-fsharp-server-capture/) (function). Acquires a replacement shared .NET `LibTmux.Server` to the requested depth. Acquisition is not atomic; retained handles do not refresh.