input - Kotlin and Gradle - Reading from stdio -

i trying execute kotlin class using command:

./gradlew -q run < src/main/kotlin/samples/input.txt 

here helloworld.kt class:

package samples  fun main(args: array<string>) {      println("hello, world!")      val lineread = readline()     println(lineread) } 

here build.gradle.kts:

plugins {     kotlin("jvm")     application }  application {     mainclassname = "samples.helloworldkt" }  dependencies {     compile(kotlin("stdlib")) }  repositories {     jcenter() } 

the code executes, data contained inside input.txt file not displayed. here output get:

hello, world! null 

i want able execute gradlew command above , input.txt stream redirected stdio. can in c++. once compile .cpp file, can run:

./my_code < input.txt 

and executes expected.

how can achieve same thing kotlin , gradle?

update: based on this answer, i've tried adding build.gradle.kts not valid syntax:

almost, doesn't work :'(

in theory

my understanding: < input.txt sets standard input gradlew process, default not forwarded program.

you want add build.gradle.kts:

run {     standardinput = system.`in` } 

sources:
https://discuss.gradle.org/t/why-doesnt-system-in-read-block-when-im-using-gradle/3308/2
https://discuss.gradle.org/t/how-can-i-execute-a-java-application-that-asks-for-user-input/3264

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in practice

these build configs same me, yet groovy works , kotlin doesn't. i'm starting think gradle kotlin dsl doesn't support standardinput term yet :/

here's working groovy version if that's help:

apply plugin: 'kotlin' apply plugin: 'application'  buildscript {     ext.kotlin_version = '1.1.4'      repositories {         jcenter()     }      dependencies {         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"     } }  repositories {     jcenter() }  dependencies {     // api => exported consumers (found on compile classpath)     // implementation => used internally (not exposed consumers)     implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version" }  mainclassname = "samples.helloworldkt"  run {     standardinput = system.in }