Fix #598: Allow external configuration of logStartupMessage via Properties and Env Vars

src/androidMain/kotlin/io/github/oshai/kotlinlogging/KotlinLoggingConfiguration.kt

@@ -36,7 +36,10 @@ public actual object KotlinLoggingConfiguration {
 
   @Volatile public actual var loggerFactory: KLoggerFactory = detectLogger()
 
-  public actual var logStartupMessage: Boolean = true
+  public actual var logStartupMessage: Boolean =
+    System.getProperty("kotlin-logging.logStartupMessage")?.toBoolean()
+      ?: System.getenv("KOTLIN_LOGGING_STARTUP_MESSAGE")?.toBoolean()
+      ?: true
 
   private fun detectLogger(): KLoggerFactory {
     if (System.getProperty("kotlin-logging-to-android-native") != null) {

src/darwinMain/kotlin/io/github/oshai/kotlinlogging/KotlinLoggingConfiguration.kt

@@ -1,13 +1,22 @@
 package io.github.oshai.kotlinlogging
 
 import kotlin.concurrent.AtomicReference
+import kotlinx.cinterop.ExperimentalForeignApi
+import kotlinx.cinterop.toKString
+import platform.posix.getenv
+
+@OptIn(ExperimentalForeignApi::class)
+private fun getEnv(name: String): String? {
+  return getenv(name)?.toKString()
+}
 
 public actual object KotlinLoggingConfiguration {
   // Existing Darwin-specific properties
   public var subsystem: AtomicReference<String?> = AtomicReference(null)
   public var category: AtomicReference<String?> = AtomicReference(null)
 
-  private val _logStartupMessage = AtomicReference(true)
+  private val _logStartupMessage =
+    AtomicReference(getEnv("KOTLIN_LOGGING_STARTUP_MESSAGE")?.toBoolean() ?: true)
   public actual var logStartupMessage: Boolean
     get() = _logStartupMessage.value
     set(value) {

src/jsMain/kotlin/io/github/oshai/kotlinlogging/KotlinLoggingConfiguration.kt

@@ -1,7 +1,33 @@
 package io.github.oshai.kotlinlogging
 
+private fun resolveStartupMessageDefault(): Boolean {
+  try {
+    val disabledInWindow =
+      js(
+        "typeof window !== 'undefined' && (window.KOTLIN_LOGGING_STARTUP_MESSAGE === 'false' || window.KOTLIN_LOGGING_STARTUP_MESSAGE === false)"
+      )
+        as Boolean
+    if (disabledInWindow) {
+      return false
+    }
+
+    val disabledInEnv =
+      js(
+        "typeof process !== 'undefined' && process.env && (process.env.KOTLIN_LOGGING_STARTUP_MESSAGE === 'false' || process.env.KOTLIN_LOGGING_STARTUP_MESSAGE === false)"
+      )
+        as Boolean
+    if (disabledInEnv) {
+      return false
+    }
+
+    return true
+  } catch (e: Throwable) {
+    return true
+  }
+}
+
 public actual object KotlinLoggingConfiguration {
-  public actual var logStartupMessage: Boolean = true
+  public actual var logStartupMessage: Boolean = resolveStartupMessageDefault()
 
   public actual val direct: DirectLoggingConfiguration =
     object : DirectLoggingConfiguration {

src/jvmMain/kotlin/io/github/oshai/kotlinlogging/KotlinLoggingConfiguration.kt

@@ -11,7 +11,10 @@ public actual object KotlinLoggingConfiguration {
    */
   @Volatile public actual var loggerFactory: KLoggerFactory = detectLogger()
 
-  public actual var logStartupMessage: Boolean = true
+  public actual var logStartupMessage: Boolean =
+    System.getProperty("kotlin-logging.logStartupMessage")?.toBoolean()
+      ?: System.getenv("KOTLIN_LOGGING_STARTUP_MESSAGE")?.toBoolean()
+      ?: true
 
   public actual val direct: DirectLoggingConfiguration =
     object : DirectLoggingConfiguration {

src/nativeMain/kotlin/io/github/oshai/kotlinlogging/KotlinLoggingConfiguration.kt

@@ -1,6 +1,14 @@
 package io.github.oshai.kotlinlogging
 
 import kotlin.concurrent.AtomicReference
+import kotlinx.cinterop.ExperimentalForeignApi
+import kotlinx.cinterop.toKString
+import platform.posix.getenv
+
+@OptIn(ExperimentalForeignApi::class)
+private fun getEnv(name: String): String? {
+  return getenv(name)?.toKString()
+}
 
 public actual object KotlinLoggingConfiguration {
   public actual val direct: DirectLoggingConfiguration =
@@ -31,7 +39,8 @@ public actual object KotlinLoggingConfiguration {
         }
     }
 
-  private val _logStartupMessage = AtomicReference(true)
+  private val _logStartupMessage =
+    AtomicReference(getEnv("KOTLIN_LOGGING_STARTUP_MESSAGE")?.toBoolean() ?: true)
   public actual var logStartupMessage: Boolean
     get() = _logStartupMessage.value
     set(value) {

src/wasmJsMain/kotlin/io/github/oshai/kotlinlogging/KotlinLoggingConfiguration.kt

@@ -1,5 +1,29 @@
 package io.github.oshai.kotlinlogging
 
+private fun startupMessageDisabledInWindow(): Boolean =
+  js(
+    "typeof window !== 'undefined' && (window.KOTLIN_LOGGING_STARTUP_MESSAGE === 'false' || window.KOTLIN_LOGGING_STARTUP_MESSAGE === false)"
+  )
+
+private fun startupMessageDisabledInEnv(): Boolean =
+  js(
+    "typeof process !== 'undefined' && process.env && (process.env.KOTLIN_LOGGING_STARTUP_MESSAGE === 'false' || process.env.KOTLIN_LOGGING_STARTUP_MESSAGE === false)"
+  )
+
+private fun resolveStartupMessageDefault(): Boolean {
+  try {
+    if (startupMessageDisabledInWindow()) {
+      return false
+    }
+    if (startupMessageDisabledInEnv()) {
+      return false
+    }
+    return true
+  } catch (e: Throwable) {
+    return true
+  }
+}
+
 public actual object KotlinLoggingConfiguration {
   public actual val direct: DirectLoggingConfiguration =
     object : DirectLoggingConfiguration {
@@ -36,5 +60,5 @@ public actual object KotlinLoggingConfiguration {
 
   public actual var loggerFactory: KLoggerFactory = DirectLoggerFactory
 
-  public actual var logStartupMessage: Boolean = true
+  public actual var logStartupMessage: Boolean = resolveStartupMessageDefault()
 }