Gradle Goodness: Checking Operating Systems in Build Scripts
Checking the OS in a build script is a common enough desire. You can do that with Gradle, but you shouldn't use the internal class that, on the face of it, would help.
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org.gradle.nativeplatform.platform.internal.DefaultOperatingSystem
But we should not use this class in our build scripts. The class is used internally by Gradle and can change without warning. If we depend on this class and it changes, we break our build scripts. But we can use a class from Ant that is already in Gradle's class path:
org.apache.tools.ant.taskdefs.condition.Os
The class has several methods and constants to check the operating system name, version, and architecture. The values are based on the Java system properties os.name
, os.version
, and os.arch
.
In the following example build script, we use import static
to include the Os
class, so we can directly invoke the methods and refer to the constants in the Os
class. We add some tasks that have a condition check with onlyIf
so the task only runs when the condition in the closure is true
. The task osInfo
simply shows values from the Os
class:
// File: build.gradle
import static org.apache.tools.ant.taskdefs.condition.Os.*
task os {
description 'Run all conditional os tasks'
}
// Create 3 tasks that simply print
// the task name that is executed
// if the build scripts runs on the
// recognized operating system.
[FAMILY_WINDOWS, FAMILY_UNIX, FAMILY_MAC].each { osName ->
// Create task.
tasks.create(osName) {
description "Run when OS is ${osName}"
// Add condition to check operating system.
onlyIf { isFamily(osName) }
doLast {
println "Execute task '${it.name}'"
}
}
// Add task as dependency for the os task.
os.dependsOn osName
}
task osInfo {
description 'Show information about the operating system'
doLast {
println "Family: ${OS_NAME}"
println "Version: ${OS_VERSION}"
println "Architecture: ${OS_ARCH}"
}
}
Let's run the os
and osInfo
tasks on MacOS:
$ gradle os osInfo
mac
Execute task 'mac'
:unix
Execute task 'unix'
:windows SKIPPED
:os
:osInfo
Family: mac os x
Version: 10.12.3
Architecture: x86_64
BUILD SUCCESSFUL
Total time: 0.697 secs
Written with Gradle 3.3.
Published at DZone with permission of Hubert Klein Ikkink, DZone MVB. See the original article here.
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