Ecosyste.ms: Awesome
An open API service indexing awesome lists of open source software.
https://github.com/scallop/scallop
a simple Scala CLI parsing library
https://github.com/scallop/scallop
Last synced: 25 days ago
JSON representation
a simple Scala CLI parsing library
- Host: GitHub
- URL: https://github.com/scallop/scallop
- Owner: scallop
- License: mit
- Created: 2012-03-22T19:17:41.000Z (over 12 years ago)
- Default Branch: develop
- Last Pushed: 2024-03-16T05:41:49.000Z (9 months ago)
- Last Synced: 2024-08-04T00:05:46.411Z (4 months ago)
- Language: Scala
- Homepage:
- Size: 3.62 MB
- Stars: 676
- Watchers: 15
- Forks: 56
- Open Issues: 6
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- Funding: .github/FUNDING.yml
- License: license.txt
Awesome Lists containing this project
- awesome-scala-native - scallop - A simple Scala CLI parsing library. (Console)
README
Scallop
========
[](https://github.com/scallop/scallop/actions?query=workflow%3A%22Continuous+Integration%22)
A simple command-line arguments parsing library for Scala.
Cross-built for Scala 3.0, 2.13, 2.12, 2.11, 2.10, supports Scala Native and Scala JS.
Scallop supports:
* flag, single-value and multiple value options
* POSIX-style short option names (-a) with grouping (-abc)
* GNU-style long option names (--opt, --opt=value)
* unnamed integer options, like GNU tail (-42)
* Property arguments (-Dkey=value, -D key1=value key2=value)
* Non-string types of options and properties values (with extendable converters)
* Powerful matching on trailing args
* Subcommands
For more info and information on usage, you can look into the [project wiki](https://github.com/scallop/scallop/wiki) or consult the [API docs](https://scallop.github.io/scallop/api/org/rogach/scallop.html).
Also, I wrote a [blog post](http://blog.rogach.org/2012/04/better-cli-option-parsing-in-scala.html) and [another one](http://blog.rogach.org/2012/04/configuration-objects-in-scallop.html) about Scallop.
Installation
============
Add following to your build.sbt:
```scala
libraryDependencies += "org.rogach" %% "scallop" % "5.1.0"
```
For use with Scala Native and Scala.js, use `%%%`:
```scala
libraryDependencies += "org.rogach" %%% "scallop" % "5.1.0"
```
If you were using `4.x` version or older, please see [migration notes](https://github.com/scallop/scallop/wiki/Migration-notes).
Quick example
=============
```scala
import org.rogach.scallop._
class Conf(arguments: Seq[String]) extends ScallopConf(arguments) {
val apples = opt[Int](required = true)
val bananas = opt[Int]()
val name = trailArg[String]()
verify()
}
object Main {
def main(args: Array[String]) {
val conf = new Conf(args)
println("apples are: " + conf.apples())
}
}
```
This snippet above defined simple configuration that will parse argument lines like these:
```
--apples 4 --bananas 10 strangeTree
-a 4 appleTree
```
For more examples, you can look at Scallop's [wiki](https://github.com/scallop/scallop/wiki) and [test suite](./jvm/src/test/scala).
Fancy things
============
Scallop supports quite powerful matching on trailing arguments. For example:
```scala
object Conf extends ScallopConf(
List("-Ekey1=value1", "key2=value2", "key3=value3",
"first", "1","2","3","second","4","5","6")) {
val properties = props[String]('E')
val firstListName = trailArg[String]()
val firstList = trailArg[List[Int]]()
val secondListName = trailArg[String]()
val secondList = trailArg[List[Double]]()
verify()
}
Conf.properties("key1") shouldBe "value1"
Conf.firstListName() shouldBe "first"
Conf.secondListName() shouldBe "second"
Conf.firstList() shouldBe List(1,2,3)
Conf.secondList() shouldBe List[Double](4,5,6)
```
In this case, Scallop's backtracking parser is clever enough to distinguish the boundaries of the arguments lists.
Also, Scallop supports parsing of subcommands. Not only subcommands, but nested subcommands!
```scala
object Conf extends ScallopConf(Seq("sub1", "sub2", "sub3", "sub4", "win!")) {
object sub1 extends Subcommand("sub1") {
object sub2 extends Subcommand("sub2") {
object sub3 extends Subcommand("sub3") {
object sub4 extends Subcommand("sub4") {
val opts = trailArg[List[String]]()
}
addSubcommand(sub4)
}
addSubcommand(sub3)
}
addSubcommand(sub2)
}
addSubcommand(sub1)
verify()
}
Conf.subcommands shouldBe List(Conf.sub1, Conf.sub1.sub2, Conf.sub1.sub2.sub3, Conf.sub1.sub2.sub3.sub4)
Conf.sub1.sub2.sub3.sub4.opts() shouldBe List("win!")
```
Thanks
======
* [Alexy Khrabrov](https://github.com/alexy)
... and the whole Scala community for help and explanations.
Notes
=====
Scallop is distributed under [MIT license](./license.txt).