tmux client library for Scala

Control tmux, connect to and create servers, navigate sessions, windows, and panes, send keys, watch for changes via control mode, capture pane contents.

Examples

Complete programs, sourced from the code each port tests.

Install

libraryDependencies += "io.github.libtmux" %% "libtmux-scala" % "0.1.0"

At a glance

Server → Session → Window → Pane. Each level of the tmux hierarchy has its own entry in the Scala API, with the tmux object it wraps.

Type	Wraps
`io.github.libtmux.scaladsl.Server`	A tmux server
`io.github.libtmux.scaladsl.Session`	A session, ID `$n`
`io.github.libtmux.scaladsl.Window`	A window in a session, ID `@n`
`io.github.libtmux.scaladsl.Pane`	A pane in a window, ID `%n`

What it does

Start with Scala

+ Error handling + Cleanup

import io.github.libtmux.{ServerConfig, ServerEndpoint}
import io.github.libtmux.scaladsl.{config => _, *}
import java.nio.file.Path
import java.time.Duration
import java.util.UUID
import scala.util.Using

object Main {
  def main(args: Array[String]): Unit = {
    val socket = s"libtmux-home-${UUID.randomUUID()}"
    val config = ServerConfig.builder()
      .endpoint(ServerEndpoint.namedSocket(socket))
      .configFile(Path.of("/dev/null"))
      .defaultTimeout(Duration.ofSeconds(5))
      .build()

    Using.resource(Server.open(config)) { server =>
      val session = server.newSession("work")
      session.newWindow("logs")

      val panes = server.panes()
      val named = panes.filter(_.info.title().nonEmpty)
      val commands = named.map(_.info.currentCommand())
      assert(panes.size == 2)

      println(s"${session.name}: ${panes.size} panes")
      println(s"commands: ${commands.distinct.sorted.mkString(", ")}")
    }
  }
}

import io.github.libtmux.{ServerConfig, ServerEndpoint}
import io.github.libtmux.scaladsl.{config => _, *}
import java.nio.file.Path
import java.time.Duration
import java.util.UUID
import scala.util.Using
import scala.util.control.NonFatal

object Main {
  def main(args: Array[String]): Unit = {
    val socket = s"libtmux-home-${UUID.randomUUID()}"
    val config = ServerConfig.builder()
      .endpoint(ServerEndpoint.namedSocket(socket))
      .configFile(Path.of("/dev/null"))
      .defaultTimeout(Duration.ofSeconds(5))
      .build()

    Using.resource(Server.open(config)) { server =>
      try {
        val session = server.newSession("work")
        session.newWindow("logs")

        val panes = server.panes()
        val named = panes.filter(_.info.title().nonEmpty)
        val commands = named.map(_.info.currentCommand())
        assert(panes.size == 2)

        println(s"${session.name}: ${panes.size} panes")
        println(s"commands: ${commands.distinct.sorted.mkString(", ")}")
      } catch {
        case NonFatal(error) =>
          throw new IllegalStateException(
            "tmux quickstart failed", error
          )
      }
    }
  }
}

import io.github.libtmux.{ServerConfig, ServerEndpoint}
import io.github.libtmux.scaladsl.{config => _, *}
import java.nio.file.Path
import java.time.Duration
import java.util.UUID
import scala.util.Using

object Main {
  def main(args: Array[String]): Unit = {
    val socket = s"libtmux-home-${UUID.randomUUID()}"
    val config = ServerConfig.builder()
      .endpoint(ServerEndpoint.namedSocket(socket))
      .configFile(Path.of("/dev/null"))
      .defaultTimeout(Duration.ofSeconds(5))
      .build()

    Using.resource(Server.open(config)) { server =>
      try {
        val session = server.newSession("work")
        session.newWindow("logs")

        val panes = server.panes()
        val named = panes.filter(_.info.title().nonEmpty)
        val commands = named.map(_.info.currentCommand())
        assert(panes.size == 2)

        println(s"${session.name}: ${panes.size} panes")
        println(s"commands: ${commands.distinct.sorted.mkString(", ")}")
      } finally {
        server.killServer()
      }
    }
  }
}

import io.github.libtmux.{ServerConfig, ServerEndpoint}
import io.github.libtmux.scaladsl.{config => _, *}
import java.nio.file.Path
import java.time.Duration
import java.util.UUID
import scala.util.Using
import scala.util.control.NonFatal

object Main {
  def main(args: Array[String]): Unit = {
    val socket = s"libtmux-home-${UUID.randomUUID()}"
    val config = ServerConfig.builder()
      .endpoint(ServerEndpoint.namedSocket(socket))
      .configFile(Path.of("/dev/null"))
      .defaultTimeout(Duration.ofSeconds(5))
      .build()

    Using.resource(Server.open(config)) { server =>
      try {
        val session = server.newSession("work")
        session.newWindow("logs")

        val panes = server.panes()
        val named = panes.filter(_.info.title().nonEmpty)
        val commands = named.map(_.info.currentCommand())
        assert(panes.size == 2)

        println(s"${session.name}: ${panes.size} panes")
        println(s"commands: ${commands.distinct.sorted.mkString(", ")}")
      } catch {
        case NonFatal(error) =>
          throw new IllegalStateException(
            "tmux quickstart failed", error
          )
      } finally {
        server.killServer()
      }
    }
  }
}

Run this example

JDK 25 and tmux on Linux/macOS; Scala 3.9.0 Direct facade

Save the program above as src/main/scala/Main.scala in a new directory, along with the files below.

Cleanup is omitted; the private tmux server and its temporary files may remain. Select Cleanup to remove them when the program finishes. The program stops its private tmux server and removes any temporary files it created when it finishes. Error handling adds diagnostics; every version checks required results and deadlines.

build.gradle.kts

plugins {
    scala
    application
}

repositories { mavenCentral() }

dependencies {
    implementation("io.github.libtmux:libtmux-scala_3:0.1.0")
    implementation("org.scala-lang:scala3-library_3:3.9.0")
}

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

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

settings.gradle.kts

rootProject.name = "api-example"

gradle.properties

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

Setup and run

# Save the files above at their displayed relative paths.
git clone https://github.com/libtmux/libtmux-java.git libtmux-source
git -C libtmux-source checkout --detach 5c181887918351119bfdb3a046719fa792048e59
./libtmux-source/gradlew --project-dir . --console=plain --no-daemon --max-workers=2 \
  installDist -PexampleMain=Main
SHELL=/bin/sh build/install/api-example/bin/api-example

Expected output

work: 2 panes
commands: sh

Library revision: 5c1818879183.

Typed API

Typed objects instead of parsed format strings: io.github.libtmux.scaladsl.Pane
Filtering and queries over tmux objects: io.github.libtmux.scaladsl.query.Expr

What you get over the tmux CLI

Connect to or start a tmux server: io.github.libtmux.scaladsl.Server.open
Traversal from a server down to its panes: io.github.libtmux.scaladsl.Server.panes
Send keys to a pane: io.github.libtmux.scaladsl.Pane.sendKeys
Watch for changes through tmux control mode: io.github.libtmux.scaladsl.Server.control
Capture pane contents: io.github.libtmux.scaladsl.Pane.capture
Arguments passed as a list, with no shell quoting: io.github.libtmux.scaladsl.Server.cmd

Scripting & web

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BEAM

tmux

tmux client library for Scala

Guides

Examples

API reference

Install

At a glance

What it does

Start with Scala

Setup and run

Expected output

Typed API

What you get over the tmux CLI