从ssh命令以与创建它的顺序相同的顺序记录stdout和stderr [英] Log stdout and stderr from ssh command in the same order it was created

问题描述

短版本：是否可以通过ssh以与远程主机上输出的顺序相同的顺序在远程执行的命令的本地端记录stdout和stderr？如果是这样，怎么样？

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?

长版本：

我正在尝试登录远程执行SSH命令（使用Jsch）的标准和错误输出顺序与远程命令输出的顺序相同。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

b b
c

a
b
c

以下是我所拥有的远。它与我想要的相对接近，但我认为很明显它不能保证客户端的输出顺序正确。

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来自Jsch网站示例的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

下面的代码块怎么样？

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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