# io.github.libtmux.kotlin.Server.panes

- **Module:** io.github.libtmux.kotlin
- **Package:** io.github.libtmux:libtmux-kotlin
- **Language:** Kotlin
- **Kind:** method
- **Source:** https://libtmux.org/en/kotlin/latest/reference/sources/libtmux-kotlin/build/generated/sources/operations/kotlin/io/github/libtmux/kotlin/ServerOperations.kt
- **Page:** https://libtmux.org/en/kotlin/latest/reference/io-github-libtmux-kotlin-server-panes/

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

```
public suspend fun Server.panes(): List<Pane>

public suspend fun Server.panes(expression: FilterExpr<io.github.libtmux.Pane>): List<Pane>
```

Captures every pane on the server.

## Examples

List all panes, then the panes captured for one window. Use JDK 25, Git, and tmux 3.2a through 3.7c on Linux, with /bin/cat and /bin/sh available. In an empty directory, fetch the documented library revision:

```console
$ git clone https://github.com/libtmux/libtmux-java.git libtmux-source && \
  git -C libtmux-source checkout f56392b5d9bc7f1f9c1631842333fb90f3d82d40
```

Save this consumer setup as settings.gradle.kts:

[Source example](https://github.com/libtmux/libtmux-java/blob/f56392b5d9bc7f1f9c1631842333fb90f3d82d40/examples/api/kotlin/settings.gradle.kts).

```kotlin
rootProject.name = "api-example"

includeBuild("libtmux-source")
```

Save this consumer setup as build.gradle.kts:

[Source example](https://github.com/libtmux/libtmux-java/blob/f56392b5d9bc7f1f9c1631842333fb90f3d82d40/examples/api/kotlin/build.gradle.kts).

```kotlin
plugins {
    kotlin("jvm") version "2.4.10"
    application
}

repositories { mavenCentral() }

dependencies {
    implementation("io.github.libtmux:libtmux-kotlin:0.0.1-alpha.17-SNAPSHOT")
}

java { toolchain { languageVersion.set(JavaLanguageVersion.of(25)) } }
kotlin { jvmToolchain(25) }

application { mainClass.set(providers.gradleProperty("exampleMain")) }
```

Save this consumer setup as gradle.properties:

[Source example](https://github.com/libtmux/libtmux-java/blob/f56392b5d9bc7f1f9c1631842333fb90f3d82d40/examples/api/gradle.properties).

```properties
org.gradle.jvmargs=-Xmx2g -XX:MaxMetaspaceSize=768m -Dfile.encoding=UTF-8
kotlin.daemon.jvmargs=-Xmx2g
org.gradle.workers.max=2
```

Save this launcher as run.sh. It creates and stops a private tmux server, including after program failure. A shutdown failure retains its socket directory and exits unsuccessfully.

[Source example](https://github.com/libtmux/libtmux-java/blob/f56392b5d9bc7f1f9c1631842333fb90f3d82d40/examples/api/run.sh).

```sh
#!/bin/sh
set -eu

if [ "$#" -eq 0 ]; then
    printf 'Usage: sh run.sh program [arguments...]\n' >&2
    exit 2
fi
binary=$(command -v "${TMUX_BIN:-tmux}")
mkdir -p /tmp/libtmux-java-dev
directory=$(mktemp -d /tmp/libtmux-java-dev/api.XXXXXX)
socket="$directory/tmux.sock"
config="$directory/tmux.conf"

alive() {
    "$binary" -S "$socket" display-message -p '#{pid}' >/dev/null 2>&1
}

cleanup() {
    status=$?
    trap - 0 HUP INT TERM
    if alive; then
        if ! "$binary" -S "$socket" kill-server; then
            printf 'Cannot stop tmux; kept %s\n' "$directory" >&2
            exit 1
        fi
        attempts=0
        while alive && [ "$attempts" -lt 100 ]; do
            sleep 0.05
            attempts=$((attempts + 1))
        done
        if alive; then
            printf 'tmux is still responding; kept %s\n' "$directory" >&2
            exit 1
        fi
    fi
    rm -rf "$directory" || exit 1
    exit "$status"
}
trap cleanup 0
trap 'exit 1' HUP INT TERM

unset TMUX TMUX_PANE
printf 'set-option -g default-shell /bin/sh\n' > "$config"
"$binary" -S "$socket" -f "$config" new-session -d -s work-one -n editor /bin/cat
"$binary" -S "$socket" split-window -h -t '=work-one:editor' /bin/cat
"$binary" -S "$socket" new-window -d -t '=work-one' -n logs /bin/cat
"$binary" -S "$socket" new-session -d -s work-two -n editor /bin/cat
"$@" "$binary" "$socket" "$config"
"$binary" -S "$socket" has-session -t '=work-one'
"$binary" -S "$socket" has-session -t '=work-two'
```

Save this complete program as src/main/kotlin/ListPanes.kt. It opens an ordinary client for the launcher's server; closing the client releases its transport.

[Source example](https://github.com/libtmux/libtmux-java/blob/f56392b5d9bc7f1f9c1631842333fb90f3d82d40/examples/src/main/kotlin/io/github/libtmux/examples/api/kotlin/ListPanes.kt).

```kotlin
package io.github.libtmux.examples.api.kotlin

import io.github.libtmux.ServerConfig
import io.github.libtmux.ServerEndpoint
import io.github.libtmux.kotlin.*
import io.github.libtmux.kotlin.query.name
import java.nio.file.Path
import kotlin.system.exitProcess
import kotlinx.coroutines.runBlocking

/** List all panes, then the panes captured for one window. */
fun main(args: Array<String>) {
    try {
        require(args.size == 3) { "expected: tmux-binary socket-path config-file" }
        val config = ServerConfig.builder()
            .binary(args[0])
            .endpoint(ServerEndpoint.socketPath(Path.of(args[1])))
            .configFile(Path.of(args[2]))
            .build()
        runBlocking {
            withServer(config) { server ->
                println("panes=${server.panes().size}")
                val session = server.session(Session.name eq "work-one")
                val window = session.windows.single { it.name == "editor" }
                println("window-panes=${window.panes.size}")
            }
        }
    } catch (error: Exception) {
        if (error is InterruptedException) Thread.currentThread().interrupt()
        System.err.println("Example failed: ${error.message}")
        exitProcess(1)
    }
}
```

Build the minimal consumer and run the saved program with the private fixture. An operation or cleanup error makes the command exit unsuccessfully:

```console
$ ./libtmux-source/gradlew --project-dir . --console=plain --quiet \
    installDist -PexampleMain=io.github.libtmux.examples.api.kotlin.ListPanesKt && \
  sh run.sh build/install/api-example/bin/api-example
```

Expected output:

```text
panes=4
window-panes=2
```

## Parameters

- `expression` (`FilterExpr<io.github.libtmux.Pane>`) (for `panes(expression)`)