按照创建顺序从 ssh 命令记录 stdout 和 stderr [英] Log stdout and stderr from ssh command in the same order it was created

问题描述

简短版本: 是否可以按照在远程主机上输出的相同顺序在通过 ssh 远程执行的命令的本地端记录 stdout 和 stderr?如果是，怎么办?

Short Version: Is it possible to log the stdout and stderr on the local side of a command executed remotely via ssh in the same order as it was output on the remote host? If so, how?

长版:

我试图以与远程命令输出相同的顺序记录远程执行的 SSH 命令(使用 Jsch)的标准和错误输出.换句话说，如果远程命令将a"写入stdout，然后将b"写入stderr，然后将c"写入stdout，我希望客户端(本地)端的日志读取:

I am attempting to log the standard and error output from a remotely exec'd SSH command (using Jsch) in the same order as it was output by the remote command. In other words, if the remote command writes "a" to stdout, then "b" to stderr, then "c" to stdout, I want the log on the client (local) side to read:

a
乙
c

a
b
c

以下是我目前所拥有的.它比较接近我想要的，但我认为很明显它不能保证客户端的正确输出顺序.

Below is what I have so far. It comes relatively close to what I want, but I think it will be apparent that it does not guarantee the correct output order on the client side.

public int exec(String strCommand) throws ExceptionUnableToExecCommand {
    JSch jsch = new JSch();
    Session session = null;
    ChannelExec channel = null;
    try {
          session = jsch.getSession(user, host, 22);
          UserInfo ui = new cyclOps.jsch.UserInfo(password);
          session.setUserInfo(ui);
          session.connect();
          channel = (ChannelExec) session.openChannel("exec");
          channel.setCommand(strCommand);
          channel.setInputStream(null);
          InputStream in = channel.getInputStream();
          InputStream err = channel.getErrStream();
          channel.connect();
          /* getOutput() defined below. */
          return this.getOutput(channel, in, err);
    } catch (JSchException | IOException e) {
        throw new ExceptionUnableToExecCommand("Unable to execute " + strCommand + " " + this.toString(), e);
    } finally {
        if (channel != null) channel.disconnect();
        if (session != null) session.disconnect();
    }
}

private int getOutput(ChannelExec channel, InputStream in, InputStream err) throws IOException { 
    byte[] tmp = new byte[1024];
    while(true){
        while(in.available() > 0){
            int i=in.read(tmp, 0, 1024);
            if(i<0)break;
            this.sshLogger.logOutputFromSSH(new String(tmp, 0, i));
        }
        while(err.available() > 0){
            int i=err.read(tmp, 0, 1024);
            if(i<0)break;
            this.sshLogger.logOutputFromSSH(new String(tmp, 0, i));
        }
        if(channel.isClosed()){
            return channel.getExitStatus();
        }
        try{Thread.sleep(1000);}catch(Exception ee){}
    }
}

我想我应该指出这是 Jsch 网站示例中 Exec.java 的修改版本.

I think I should point out that this is a modified version of Exec.java from the Jsch web site examples.

推荐答案

下面这段代码怎么样?

channel.setCommand(command);

PipedOutputStream pos=new PipedOutputStream();
PipedInputStream pis=new PipedInputStream(pos);
channel.setOutputStream(pos);
channel.setExtOutputStream(pos);
InputStream in=pis;

channel.connect();

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