# LibTmux.FSharp.Window.rename

- **Module:** LibTmux.FSharp
- **Package:** LibTmux.FSharp
- **Language:** F#
- **Kind:** function
- **Source:** https://github.com/libtmux/libtmux-dotnet/blob/cf34b255c896d19a97e7d7fabea58609c916012d/src/LibTmux.FSharp/Hierarchy.fsi#L158
- **Page:** https://libtmux.org/en/fsharp/latest/reference/libtmux-fsharp-window-rename/

```
val rename: cancellationToken: CancellationToken -> name: string -> window: LibTmux.Window -> Task<LibTmux.Window>
```

Renames the window and returns a handle carrying the new name.

tmux expands the name as a format, so a <c>#</c> in it does not survive verbatim.

## Examples

Create owned session and window scopes with the core LibTmux API, split a pane with Pane.split, then rename and select the window, select the first pane again, arrange the window, title the pane and kill the split with the F# helpers. Renaming and selecting return a handle carrying the state afterwards. Disposing the owned window also stops its panes. For F# session descriptions, use Server.newSession with SessionSpec. Use Linux or macOS with Git, tmux 3.2a or newer, .NET SDK 10.0.303, and the .NET 8 and 10 runtimes. In an empty directory, fetch the documented library revision:

```console
$ git clone https://github.com/libtmux/libtmux-dotnet.git libtmux-source && \
  git -C libtmux-source checkout --detach cf34b255c896d19a97e7d7fabea58609c916012d
```

Save this complete consumer setup as global.json:

[Source example](https://github.com/libtmux/libtmux-dotnet/blob/cf34b255c896d19a97e7d7fabea58609c916012d/global.json).

```json
{
  "sdk": {
    "version": "10.0.303",
    "rollForward": "disable",
    "allowPrerelease": false
  },
  "test": {
    "runner": "Microsoft.Testing.Platform"
  }
}
```

Save this complete consumer setup as NuGet.config:

[Source example](https://github.com/libtmux/libtmux-dotnet/blob/cf34b255c896d19a97e7d7fabea58609c916012d/examples/api/NuGet.config).

```xml
<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <packageSources>
    <clear />
    <add key="libtmux-source" value="libtmux-source/artifacts/api-example-packages" />
    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" />
  </packageSources>
  <packageSourceMapping>
    <clear />
    <packageSource key="libtmux-source">
      <package pattern="LibTmux" />
      <package pattern="LibTmux.*" />
    </packageSource>
    <packageSource key="nuget.org">
      <package pattern="*" />
    </packageSource>
  </packageSourceMapping>
</configuration>
```

Save this complete consumer setup as Example.fsproj:

[Source example](https://github.com/libtmux/libtmux-dotnet/blob/cf34b255c896d19a97e7d7fabea58609c916012d/examples/api/fsharp/Example.fsproj).

```xml
<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFrameworks>net8.0;net10.0</TargetFrameworks>
    <LangVersion>10.0</LangVersion>
    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
    <DisableImplicitFSharpCoreReference>true</DisableImplicitFSharpCoreReference>
    <DisableImplicitLibraryPacksFolder>true</DisableImplicitLibraryPacksFolder>
  </PropertyGroup>
  <ItemGroup>
    <Compile Include="Program.fs" />
    <PackageReference Include="FSharp.Core" Version="[10.1.303]" />
    <PackageReference Include="LibTmux.FSharp" Version="[0.0.0-alpha.20]" />
  </ItemGroup>
</Project>
```

Save this complete program as Program.fs. It creates a private server with LibTmux.Server.CreateOwnedAsync; use! disposes owned scopes after success, cancellation or failure. The F# facade has no separate server constructor.

[Source example](https://github.com/libtmux/libtmux-dotnet/blob/cf34b255c896d19a97e7d7fabea58609c916012d/examples/LibTmux.FSharp.Examples/Programs/CreateWindowPane.fs).

```fsharp
open System
open System.Threading
open LibTmux
open LibTmux.FSharp

let runAsync () =
    task {
        use deadline = new CancellationTokenSource(TimeSpan.FromSeconds 10.)
        let token = deadline.Token

        let options =
            ServerConnectionOptions(
                SocketName = "fsharp-create-" + Guid.NewGuid().ToString("N"),
                ConfigurationFile = "/dev/null"
            )

        use! owned = options |> Server.createOwned token

        use! session =
            owned.Value.CreateOwnedSessionAsync(
                NewSessionRequest(Name = "demo", WindowName = "shell", Command = "/bin/cat"),
                token
            )

        use! window =
            session.Value.CreateOwnedWindowAsync(
                NewWindowRequest(Name = "editor", Command = "/bin/cat", Attach = false),
                token
            )

        let! panes = window.Value.GetPanesAsync(token)
        let original = panes |> Seq.exactlyOne

        let! added =
            original
            |> Pane.split token (SplitPaneRequest(Direction = PaneDirection.Right, Command = "/bin/cat"))

        // Renaming and selecting return a handle carrying the state afterwards.
        let! notes = window.Value |> Window.rename token "notes"
        let wasCurrent = notes.Active
        let! current = notes |> Window.select token
        let! focused = original |> Pane.select token
        let! _ = current |> Window.selectLayout token "even-horizontal"
        let! titled = focused |> Pane.setTitle token "editor"
        do! added |> Pane.kill token

        let server = owned.Value
        let! windows = server |> Server.windows |> Query.list token
        let! allPanes = server |> Server.panes |> Query.list token

        printfn "Created session demo and window editor."
        printfn "The split made a new pane: %b" (added.Id <> original.Id)
        printfn "Renamed to %s; current before select: %b, after: %b" current.Name wasCurrent current.Active
        printfn "First pane active again: %b; titled %s" focused.Active titled.Title
        printfn "Windows: %d; panes after the kill: %d" windows.Count allPanes.Count
    }

runAsync().GetAwaiter().GetResult()
```

Build the exact source packages and the saved consumer, then run both supported frameworks. The local package feed prevents an unrelated published package from satisfying the restore. Each program checks its result and exits unsuccessfully after an unhandled error:

```console
$ export NUGET_PACKAGES="$PWD/packages" && \
  dotnet restore libtmux-source/src/LibTmux.FSharp/LibTmux.FSharp.fsproj --locked-mode && \
  dotnet pack libtmux-source/src/LibTmux/LibTmux.csproj \
    --configuration Release --no-restore -p:ContinuousIntegrationBuild=true \
    --output "$PWD/libtmux-source/artifacts/api-example-packages" && \
  dotnet pack libtmux-source/src/LibTmux.FSharp/LibTmux.FSharp.fsproj \
    --configuration Release --no-restore -p:ContinuousIntegrationBuild=true \
    --output "$PWD/libtmux-source/artifacts/api-example-packages" && \
  dotnet restore Example.fsproj --configfile NuGet.config && \
  dotnet build Example.fsproj --configuration Release --no-restore --warnaserror && \
  export LIBTMUX_TMUX="$(command -v tmux)" && \
  export TMUX_TMPDIR=/tmp/libtmux-dotnet-dev && \
  mkdir -p "$TMUX_TMPDIR" && \
  unset TMUX TMUX_PANE && \
  dotnet bin/Release/net8.0/Example.dll && \
  dotnet bin/Release/net10.0/Example.dll
```

Expected program output from each framework:

```text
Created session demo and window editor.
The split made a new pane: true
Renamed to notes; current before select: false, after: true
First pane active again: true; titled editor
Windows: 2; panes after the kill: 2
```

## Parameters

- `cancellationToken` (`CancellationToken`)
- `name` (`string`)
- `window` (`LibTmux.Window`)