Class StandardOutputStream

  • All Implemented Interfaces:
    Closeable, Flushable, AutoCloseable

    public class StandardOutputStream
    extends OutputStream
    Hint that indicates that we are using stdout with fd=1 as the stream to write to for the channel.

    Using stdin/stdout pair for the communication is very convenient for setting up a remote channel, so Jenkins tends to do that, but even with our using System.setOut(PrintStream) to avoid other parts of the Java code to accidentally corrupt the stream, file descriptor 1 continues to point to the stream we use, so native code in JVM can still accidentally pollute the stream.

    Fixing that requires the use of dup and close POSIX API calls, which we can only do after the communication gets established and JNA is brought in via remoting. Having Launcher uses this wrapper class allows us to do that without recreating the stream.

    When a channel uses StandardOutputStream to communicate, the convention is to make that object available as a channel property.

    Kohsuke Kawaguchi