Determine if only one instance is running: Difference between revisions
Determine if only one instance is running (view source)
Revision as of 18:28, 19 January 2017
, 7 years agoAdded Kotlin
SqrtNegInf (talk | contribs) m (→{{header|Perl 6}}: args to 'link' were reversed) |
(Added Kotlin) |
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Line 564:
}</lang>
=={{header|Kotlin}}==
<lang scala>// version 1.0.6
import java.io.IOException
import java.net.*
object SingleInstance {
private var ss: ServerSocket? = null
fun alreadyRunning(): Boolean {
try {
ss = ServerSocket(65000, 10, InetAddress.getLocalHost()) // using private port 65000
}
catch (e: IOException) {
// port already in use so an instance is already running
return true
}
return false
}
fun close() {
if (ss == null || ss?.isClosed() == true) return
ss?.close()
}
}
fun main(args: Array<String>) {
if (SingleInstance.alreadyRunning()) {
println("Application is already running, so terminating this instance")
System.exit(0)
}
else {
println("OK, only this instance is running but will terminate in 10 seconds")
Thread.sleep(10000)
SingleInstance.close()
}
}</lang>
{{out}}
First output window:
<pre>
OK, only this instance is running but will terminate in 10 seconds
</pre>
{{out}}
Second output window (second instance started within 10 seconds of first):
<pre>
Application is already running, so terminating this instance
</pre>
=={{header|Lasso}}==
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