使用 playframework 执行 nohup 命令获取错误的文件描述符错误

Question

我使用 playframework2.2 和 sbt 0.13.1，我可以运行 sbt 并在命令行启动服务器

sbt 开始

它工作正常。但是当我跑步时：

nohup sbt 开始

它运行了一段时间，然后因日志错误而停止：

(Starting server. Type Ctrl+D to exit logs, the server will remain in background)  java.io.IOException: Bad file descriptor
at java.io.FileInputStream.read0(Native Method)
at java.io.FileInputStream.read(FileInputStream.java:210)
at jline.internal.NonBlockingInputStream.read(NonBlockingInputStream.java:248)
at jline.internal.InputStreamReader.read(InputStreamReader.java:261)
at jline.internal.InputStreamReader.read(InputStreamReader.java:198)
at jline.console.ConsoleReader.readCharacter(ConsoleReader.java:2038)
at  play.PlayConsoleInteractionMode$$anonfun$waitForKey$1.play$PlayConsoleInteractionMode$$anonfun$$waitEOF$1(PlayInteractionMode.scala:36)
at play.PlayConsoleInteractionMode$$anonfun$waitForKey$1$$anonfun$apply$1.apply$mcV$sp(PlayInteractionMode.scala:45)
at play.PlayConsoleInteractionMode$$anonfun$doWithoutEcho$1.apply(PlayInteractionMode.scala:52)
at play.PlayConsoleInteractionMode$$anonfun$doWithoutEcho$1.apply(PlayInteractionMode.scala:49)
at play.PlayConsoleInteractionMode$.withConsoleReader(PlayInteractionMode.scala:31)
at play.PlayConsoleInteractionMode$.doWithoutEcho(PlayInteractionMode.scala:49)
at play.PlayConsoleInteractionMode$$anonfun$waitForKey$1.apply(PlayInteractionMode.scala:45)
at play.PlayConsoleInteractionMode$$anonfun$waitForKey$1.apply(PlayInteractionMode.scala:34)
at play.PlayConsoleInteractionMode$.withConsoleReader(PlayInteractionMode.scala:31)
at play.PlayConsoleInteractionMode$.waitForKey(PlayInteractionMode.scala:34)
at play.PlayConsoleInteractionMode$.waitForCancel(PlayInteractionMode.scala:55)
at play.PlayRun$$anonfun$24$$anonfun$apply$9.apply(PlayRun.scala:373)
at play.PlayRun$$anonfun$24$$anonfun$apply$9.apply(PlayRun.scala:352)
at scala.util.Either$RightProjection.map(Either.scala:536)
at play.PlayRun$$anonfun$24.apply(PlayRun.scala:352)
at play.PlayRun$$anonfun$24.apply(PlayRun.scala:334)
at sbt.Command$$anonfun$sbt$Command$$apply1$1$$anonfun$apply$6.apply(Command.scala:72)
at sbt.Command$.process(Command.scala:95)
at sbt.MainLoop$$anonfun$1$$anonfun$apply$1.apply(MainLoop.scala:100)
at sbt.MainLoop$$anonfun$1$$anonfun$apply$1.apply(MainLoop.scala:100)
at sbt.State$$anon$1.process(State.scala:179)
at sbt.MainLoop$$anonfun$1.apply(MainLoop.scala:100)
at sbt.MainLoop$$anonfun$1.apply(MainLoop.scala:100)
at sbt.ErrorHandling$.wideConvert(ErrorHandling.scala:18)
at sbt.MainLoop$.next(MainLoop.scala:100)
at sbt.MainLoop$.run(MainLoop.scala:93)
at sbt.MainLoop$$anonfun$runWithNewLog$1.apply(MainLoop.scala:71)
at sbt.MainLoop$$anonfun$runWithNewLog$1.apply(MainLoop.scala:66)
at sbt.Using.apply(Using.scala:25)
at sbt.MainLoop$.runWithNewLog(MainLoop.scala:66)
at sbt.MainLoop$.runAndClearLast(MainLoop.scala:49)
at sbt.MainLoop$.runLoggedLoop(MainLoop.scala:33)
at sbt.MainLoop$.runLogged(MainLoop.scala:25)
at sbt.StandardMain$.runManaged(Main.scala:57)
at sbt.xMain.run(Main.scala:29)
at xsbt.boot.Launch$$anonfun$run$1.apply(Launch.scala:57)
at xsbt.boot.Launch$.withContextLoader(Launch.scala:77)
at xsbt.boot.Launch$.run(Launch.scala:57)
at xsbt.boot.Launch$$anonfun$explicit$1.apply(Launch.scala:45)
at xsbt.boot.Launch$.launch(Launch.scala:65)
at xsbt.boot.Launch$.apply(Launch.scala:16)
at xsbt.boot.Boot$.runImpl(Boot.scala:32)
at xsbt.boot.Boot$.main(Boot.scala:21)
at xsbt.boot.Boot.main(Boot.scala)
error[0m] [0mjava.io.IOException: Bad file descriptor[0m
error[0m] [0mUse 'last' for the full log.[0m

任何人都知道哪个文件是错误的文件描述符。以及如何解决这个问题。

Answer 1

发生错误是因为标准输入从/dev/null 被nohup 重定向 - 如果你这样做play start < /dev/null，你会得到同样的错误。 sbt 进程在一个单独的进程中启动实际的服务器，设置自己显示日志并等待您键入 Ctrl-D 或 Ctrl-C。它使用 JLine 等待用户输入，它尝试将标准输入作为终端连接。 /dev/null 不能以这种方式使用，因此它会抱怨文件描述符错误而死。但是，后台服务器进程继续运行。

如果您想以非交互方式启动 Play，则需要使用阶段任务。请参阅 Play 文档中的 Using the stage task。