The Scala library that provides extension methods to Apache Commons CLI.
This project is archived and read-only.
To get started, add little-cli to your project:
libraryDependencies += "com.github.losizm" %% "little-cli" % "2.0.0"There's a runtime dependency to Apache Commons CLI, so you'll need to add that too.
libraryDependencies += "commons-cli" % "commons-cli" % "1.4"NOTE: Starting with version 1.0, little-cli is written for Scala 3 exclusively. See previous releases for compatibility with Scala 2.12 and Scala 2.13.
Here's an example showing the library in action.
import little.cli.{ *, given }
import Cli.{ application, option }
// Create application with supplied usage and options
val app = application("grep [ options ... ] <pattern> [ <fileName> ... ]",
option("i", "ignore-case", false, "Perform case insensitive matching"),
option("l", "files-with-matches", false, "Print file name only"),
option("m", "max-count", true, "Stop reading file after 'num' matches").argName("num"),
option("n", "line-number", false, "Include line number of match"),
option("r", "recursive", false, "Recursively search subdirectories"),
option("x", "exclude", true, "Exclude filename pattern from search").argName("pattern")
)
val args = Array("-ilr", "--exclude", "*.swp", "exception", "src/main/scala")
// Parse arguments
val cmd = app.parse(args)
cmd.hasOption("help") match
case true =>
// Print help to System.out
app.printHelp()
case false =>
// Get command arguments and pretend to do something
val pattern = cmd.getArg(0)
val fileName = cmd.getArg(1)
println(s"Searching for files with '$pattern' in $fileName directory...")Option values and arguments can be mapped to types other than String by adding
a given ValueMapper[T] to scope. There are default implementations for Int,
Long, File, and Path. Feel free to define your own for other types.
import java.io.File
import little.cli.{ *, given }
import Cli.{ application, option }
case class KeepAlive(idleTimeout: Int, maxRequests: Int)
// Define how to map value to KeepAlive
given ValueMapper[KeepAlive] =
_.split(":") match
case Array(timeout, max) => KeepAlive(timeout.toInt, max.toInt)
val app = application("start-server [ options ... ] port",
option("d", "directory", true, "Location of public files directory"),
option("k", "keep-alive", true, "Allow persistent connections").argName("timeout:max")
)
val cmd = app.parse("-d ./public_html --keep-alive 5:10 8080".split("\\s+"))
// Map keep-alive option
val keepAlive = cmd.mapOptionValue[KeepAlive]("keep-alive")
// Map directory option
val directory = cmd.mapOptionValue[File]("directory")
// Map port argument
val port = cmd.mapArg[Int](0)At times, you may need to check multiple options, possibly from a group of
mutually exclusive options, to determine what action to take. For those
occasions, you have the overloaded hasOption extension method to
CommandLine.
import java.io.{ ByteArrayInputStream, FileInputStream }
import little.cli.{ *, given }
import Cli.{ application, group, option }
val app = application("post-request [ options ... ] url",
option("H", true, "Add header").argName("header"),
// Define group of mutually exclusive options
group(
option("d", true, "Use supplied inline data").argName("data"),
option("f", true, "Use data from supplied file").argName("file"),
option("s", false, "Use data from stdin (default)")
)
)
val cmd = app.parse("-f ./message.json http://localhost:8080/messages".split("\\s+"))
// Check option group and assign input stream
val in = cmd.hasOptions("d", "f", "s") match {
case (true, _, _) => ByteArrayInputStream(cmd.getOptionValue("d").getBytes)
case (_, true, _) => FileInputStream(cmd.getOptionValue("f"))
case _ => System.in
}
val url = cmd.getArg(0)See scaladoc for additional details.
little-cli is licensed under the Apache License, Version 2. See LICENSE for more information.
