Execution of SSH command from Java sends status code 255, but in the terminal if it works

-1

I am trying to develop a small application that allows me to send certain commands by SSH to a remote server. If I try it from the Linux terminal or from the Windows Command Prompt it works without problems, but when I do it from my Java application it always responds with a status code of 255.

I have disabled the firewall and I have changed the port where I have listening SSH on the server to 22, because I use another, but nothing works. It does not throw me exceptions or anything and if it connects without problems. Any ideas?

I have tried with the sshj and JSch libraries and with both I have the same problem.

ForwardAgent is turn off

sshj example

private void sshj() throws Exception {

    SSHClient ssh = new SSHClient();

    ssh.addHostKeyVerifier((s, i, publicKey) -> true);

    ssh.connect("host", 22);

    Session session = null;

    try {

        ssh.authPassword("username", "password");

        session = ssh.startSession();

        Session.Command cmd = session.exec("command");

        System.out.println(IOUtils.readFully(cmd.getInputStream()).toString());

        cmd.join(5, TimeUnit.SECONDS);

        System.out.println("Exit status: " + cmd.getExitStatus());

    } catch (Exception e) {

        e.printStackTrace();

    } finally {

        if (session != null) {

            session.close();

        }



        ssh.disconnect();

    }

}

JSch example

private static void jsch() throws Exception {

    JSch js = new JSch();

    Session s = js.getSession("username", "host", 22);

    s.setPassword("password");

    Properties config = new Properties();

    config.put("StrictHostKeyChecking", "no");

    s.setConfig(config);

    s.connect();



    Channel c = s.openChannel("exec");

    ChannelExec ce = (ChannelExec) c;

    ce.setCommand("command");

    ce.connect();



    BufferedReader reader = new BufferedReader(new InputStreamReader(ce.getInputStream()));

    String line;

    while ((line = reader.readLine()) != null) {

        System.out.println(line);

    }



    ce.disconnect();

    s.disconnect();



    System.out.println("Exit status: " + ce.getExitStatus());

}

edited Nov 21 '18 at 1:20

asked Nov 21 '18 at 0:43

E. Betanzos

1563

Use ce.getErrStream() to see error messages.

– Martin Prikryl
Nov 21 '18 at 7:40

Though I guess you have a problem similar to this one: Certain Unix commands fail with “… not found”, when executed through Java using JSch.

– Martin Prikryl
Nov 21 '18 at 7:41

Possible duplicate of Certain Unix commands fail with "... not found", when executed through Java using JSch

– Martin Prikryl
Nov 28 '18 at 6:32

add a comment |

-1

I have tried with the sshj and JSch libraries and with both I have the same problem.

ForwardAgent is turn off

sshj example

private void sshj() throws Exception {

    SSHClient ssh = new SSHClient();

    ssh.addHostKeyVerifier((s, i, publicKey) -> true);

    ssh.connect("host", 22);

    Session session = null;

    try {

        ssh.authPassword("username", "password");

        session = ssh.startSession();

        Session.Command cmd = session.exec("command");

        System.out.println(IOUtils.readFully(cmd.getInputStream()).toString());

        cmd.join(5, TimeUnit.SECONDS);

        System.out.println("Exit status: " + cmd.getExitStatus());

    } catch (Exception e) {

        e.printStackTrace();

    } finally {

        if (session != null) {

            session.close();

        }



        ssh.disconnect();

    }

}

JSch example

private static void jsch() throws Exception {

    JSch js = new JSch();

    Session s = js.getSession("username", "host", 22);

    s.setPassword("password");

    Properties config = new Properties();

    config.put("StrictHostKeyChecking", "no");

    s.setConfig(config);

    s.connect();



    Channel c = s.openChannel("exec");

    ChannelExec ce = (ChannelExec) c;

    ce.setCommand("command");

    ce.connect();



    BufferedReader reader = new BufferedReader(new InputStreamReader(ce.getInputStream()));

    String line;

    while ((line = reader.readLine()) != null) {

        System.out.println(line);

    }



    ce.disconnect();

    s.disconnect();



    System.out.println("Exit status: " + ce.getExitStatus());

}

edited Nov 21 '18 at 1:20

asked Nov 21 '18 at 0:43

E. Betanzos

1563

Use ce.getErrStream() to see error messages.

– Martin Prikryl
Nov 21 '18 at 7:40

Though I guess you have a problem similar to this one: Certain Unix commands fail with “… not found”, when executed through Java using JSch.

– Martin Prikryl
Nov 21 '18 at 7:41

Possible duplicate of Certain Unix commands fail with "... not found", when executed through Java using JSch

– Martin Prikryl
Nov 28 '18 at 6:32

add a comment |

-1

I have tried with the sshj and JSch libraries and with both I have the same problem.

ForwardAgent is turn off

sshj example

private void sshj() throws Exception {

    SSHClient ssh = new SSHClient();

    ssh.addHostKeyVerifier((s, i, publicKey) -> true);

    ssh.connect("host", 22);

    Session session = null;

    try {

        ssh.authPassword("username", "password");

        session = ssh.startSession();

        Session.Command cmd = session.exec("command");

        System.out.println(IOUtils.readFully(cmd.getInputStream()).toString());

        cmd.join(5, TimeUnit.SECONDS);

        System.out.println("Exit status: " + cmd.getExitStatus());

    } catch (Exception e) {

        e.printStackTrace();

    } finally {

        if (session != null) {

            session.close();

        }



        ssh.disconnect();

    }

}

JSch example

private static void jsch() throws Exception {

    JSch js = new JSch();

    Session s = js.getSession("username", "host", 22);

    s.setPassword("password");

    Properties config = new Properties();

    config.put("StrictHostKeyChecking", "no");

    s.setConfig(config);

    s.connect();



    Channel c = s.openChannel("exec");

    ChannelExec ce = (ChannelExec) c;

    ce.setCommand("command");

    ce.connect();



    BufferedReader reader = new BufferedReader(new InputStreamReader(ce.getInputStream()));

    String line;

    while ((line = reader.readLine()) != null) {

        System.out.println(line);

    }



    ce.disconnect();

    s.disconnect();



    System.out.println("Exit status: " + ce.getExitStatus());

}

edited Nov 21 '18 at 1:20

asked Nov 21 '18 at 0:43

E. Betanzos

1563

I have tried with the sshj and JSch libraries and with both I have the same problem.

ForwardAgent is turn off

sshj example

private void sshj() throws Exception {

    SSHClient ssh = new SSHClient();

    ssh.addHostKeyVerifier((s, i, publicKey) -> true);

    ssh.connect("host", 22);

    Session session = null;

    try {

        ssh.authPassword("username", "password");

        session = ssh.startSession();

        Session.Command cmd = session.exec("command");

        System.out.println(IOUtils.readFully(cmd.getInputStream()).toString());

        cmd.join(5, TimeUnit.SECONDS);

        System.out.println("Exit status: " + cmd.getExitStatus());

    } catch (Exception e) {

        e.printStackTrace();

    } finally {

        if (session != null) {

            session.close();

        }



        ssh.disconnect();

    }

}

JSch example

private static void jsch() throws Exception {

    JSch js = new JSch();

    Session s = js.getSession("username", "host", 22);

    s.setPassword("password");

    Properties config = new Properties();

    config.put("StrictHostKeyChecking", "no");

    s.setConfig(config);

    s.connect();



    Channel c = s.openChannel("exec");

    ChannelExec ce = (ChannelExec) c;

    ce.setCommand("command");

    ce.connect();



    BufferedReader reader = new BufferedReader(new InputStreamReader(ce.getInputStream()));

    String line;

    while ((line = reader.readLine()) != null) {

        System.out.println(line);

    }



    ce.disconnect();

    s.disconnect();



    System.out.println("Exit status: " + ce.getExitStatus());

}

java ssh jsch sshj

edited Nov 21 '18 at 1:20

asked Nov 21 '18 at 0:43

E. Betanzos

1563

edited Nov 21 '18 at 1:20

asked Nov 21 '18 at 0:43

E. Betanzos

1563

edited Nov 21 '18 at 1:20

asked Nov 21 '18 at 0:43

E. Betanzos

1563

asked Nov 21 '18 at 0:43

E. Betanzos

1563

asked Nov 21 '18 at 0:43

E. Betanzos

1563

Use ce.getErrStream() to see error messages.

– Martin Prikryl
Nov 21 '18 at 7:40

Though I guess you have a problem similar to this one: Certain Unix commands fail with “… not found”, when executed through Java using JSch.

– Martin Prikryl
Nov 21 '18 at 7:41

Possible duplicate of Certain Unix commands fail with "... not found", when executed through Java using JSch

– Martin Prikryl
Nov 28 '18 at 6:32

add a comment |

Use ce.getErrStream() to see error messages.

– Martin Prikryl
Nov 21 '18 at 7:40

Though I guess you have a problem similar to this one: Certain Unix commands fail with “… not found”, when executed through Java using JSch.

– Martin Prikryl
Nov 21 '18 at 7:41

Possible duplicate of Certain Unix commands fail with "... not found", when executed through Java using JSch

– Martin Prikryl
Nov 28 '18 at 6:32

Use ce.getErrStream() to see error messages.

– Martin Prikryl
Nov 21 '18 at 7:40

Though I guess you have a problem similar to this one: Certain Unix commands fail with “… not found”, when executed through Java using JSch.

– Martin Prikryl
Nov 21 '18 at 7:41

Possible duplicate of Certain Unix commands fail with "... not found", when executed through Java using JSch

– Martin Prikryl
Nov 28 '18 at 6:32

add a comment |

1 Answer
1

active

oldest

votes

change to code so that you get the inputStream before doing connect

InputStream in = ce.getInputStream();

ce.connect();

BufferedReader reader = new BufferedReader(new InputStreamReader(in));

Also, the getSession is wrong as it should be

public Session getSession(String username,

                      String host,

                      int port)

edit

The below code works for me

JSch js = new JSch();

Session s = js.getSession("username", "127.0.0.1", 22);

s.setPassword("password");

Properties config = new Properties();

config.put("StrictHostKeyChecking", "no");

s.setConfig(config);

s.connect();



Channel c = s.openChannel("exec");

ChannelExec ce = (ChannelExec) c;

ce.setCommand("uptime");



InputStream in = ce.getInputStream();

ce.connect();



BufferedReader reader = new BufferedReader(new InputStreamReader(in));

String line;

while ((line = reader.readLine()) != null) {

      System.out.println(line);

}



ce.disconnect();

s.disconnect();



System.out.println("Exit status: " + ce.getExitStatus());

output

 10:26:08 up 149 days, 58 min,  3 users,  load average: 0.61, 0.68, 0.68

Exit status: 0

edited Nov 21 '18 at 1:28

answered Nov 21 '18 at 0:55

Scary Wombat

35.2k32252

No work, same behavior.

– E. Betanzos
Nov 21 '18 at 1:14

I have made more edits, also I am assuming that this is replaced with a real command ce.setCommand("command");

– Scary Wombat
Nov 21 '18 at 1:18

I have the getSession call good in my code, like you. That was an translattion error. Yes, I replace command with a real command, and work fine in terminal but in my code no.

– E. Betanzos
Nov 21 '18 at 1:23

see my latest edit

– Scary Wombat
Nov 21 '18 at 1:28

Hmm, Mr Betanzos has gone away?

– Scary Wombat
Nov 21 '18 at 1:48

add a comment |

Your Answer

StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});

}
});

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53403744%2fexecution-of-ssh-command-from-java-sends-status-code-255-but-in-the-terminal-if%23new-answer', 'question_page');
}
);

Post as a guest

Name

Required, but never shown

1 Answer
1

active

oldest

votes

1 Answer
1

active

oldest

votes

change to code so that you get the inputStream before doing connect

InputStream in = ce.getInputStream();

ce.connect();

BufferedReader reader = new BufferedReader(new InputStreamReader(in));

Also, the getSession is wrong as it should be

public Session getSession(String username,

                      String host,

                      int port)

edit

The below code works for me

JSch js = new JSch();

Session s = js.getSession("username", "127.0.0.1", 22);

s.setPassword("password");

Properties config = new Properties();

config.put("StrictHostKeyChecking", "no");

s.setConfig(config);

s.connect();



Channel c = s.openChannel("exec");

ChannelExec ce = (ChannelExec) c;

ce.setCommand("uptime");



InputStream in = ce.getInputStream();

ce.connect();



BufferedReader reader = new BufferedReader(new InputStreamReader(in));

String line;

while ((line = reader.readLine()) != null) {

      System.out.println(line);

}



ce.disconnect();

s.disconnect();



System.out.println("Exit status: " + ce.getExitStatus());

output

 10:26:08 up 149 days, 58 min,  3 users,  load average: 0.61, 0.68, 0.68

Exit status: 0

edited Nov 21 '18 at 1:28

answered Nov 21 '18 at 0:55

Scary Wombat

35.2k32252

No work, same behavior.

– E. Betanzos
Nov 21 '18 at 1:14

I have made more edits, also I am assuming that this is replaced with a real command ce.setCommand("command");

– Scary Wombat
Nov 21 '18 at 1:18

I have the getSession call good in my code, like you. That was an translattion error. Yes, I replace command with a real command, and work fine in terminal but in my code no.

– E. Betanzos
Nov 21 '18 at 1:23

see my latest edit

– Scary Wombat
Nov 21 '18 at 1:28

Hmm, Mr Betanzos has gone away?

– Scary Wombat
Nov 21 '18 at 1:48

add a comment |

change to code so that you get the inputStream before doing connect

InputStream in = ce.getInputStream();

ce.connect();

BufferedReader reader = new BufferedReader(new InputStreamReader(in));

Also, the getSession is wrong as it should be

public Session getSession(String username,

                      String host,

                      int port)

edit

The below code works for me

JSch js = new JSch();

Session s = js.getSession("username", "127.0.0.1", 22);

s.setPassword("password");

Properties config = new Properties();

config.put("StrictHostKeyChecking", "no");

s.setConfig(config);

s.connect();



Channel c = s.openChannel("exec");

ChannelExec ce = (ChannelExec) c;

ce.setCommand("uptime");



InputStream in = ce.getInputStream();

ce.connect();



BufferedReader reader = new BufferedReader(new InputStreamReader(in));

String line;

while ((line = reader.readLine()) != null) {

      System.out.println(line);

}



ce.disconnect();

s.disconnect();



System.out.println("Exit status: " + ce.getExitStatus());

output

 10:26:08 up 149 days, 58 min,  3 users,  load average: 0.61, 0.68, 0.68

Exit status: 0

edited Nov 21 '18 at 1:28

answered Nov 21 '18 at 0:55

Scary Wombat

35.2k32252

No work, same behavior.

– E. Betanzos
Nov 21 '18 at 1:14

I have made more edits, also I am assuming that this is replaced with a real command ce.setCommand("command");

– Scary Wombat
Nov 21 '18 at 1:18

I have the getSession call good in my code, like you. That was an translattion error. Yes, I replace command with a real command, and work fine in terminal but in my code no.

– E. Betanzos
Nov 21 '18 at 1:23

see my latest edit

– Scary Wombat
Nov 21 '18 at 1:28

Hmm, Mr Betanzos has gone away?

– Scary Wombat
Nov 21 '18 at 1:48

add a comment |

change to code so that you get the inputStream before doing connect

InputStream in = ce.getInputStream();

ce.connect();

BufferedReader reader = new BufferedReader(new InputStreamReader(in));

Also, the getSession is wrong as it should be

public Session getSession(String username,

                      String host,

                      int port)

edit

The below code works for me

JSch js = new JSch();

Session s = js.getSession("username", "127.0.0.1", 22);

s.setPassword("password");

Properties config = new Properties();

config.put("StrictHostKeyChecking", "no");

s.setConfig(config);

s.connect();



Channel c = s.openChannel("exec");

ChannelExec ce = (ChannelExec) c;

ce.setCommand("uptime");



InputStream in = ce.getInputStream();

ce.connect();



BufferedReader reader = new BufferedReader(new InputStreamReader(in));

String line;

while ((line = reader.readLine()) != null) {

      System.out.println(line);

}



ce.disconnect();

s.disconnect();



System.out.println("Exit status: " + ce.getExitStatus());

output

 10:26:08 up 149 days, 58 min,  3 users,  load average: 0.61, 0.68, 0.68

Exit status: 0

edited Nov 21 '18 at 1:28

answered Nov 21 '18 at 0:55

Scary Wombat

35.2k32252

change to code so that you get the inputStream before doing connect

InputStream in = ce.getInputStream();

ce.connect();

BufferedReader reader = new BufferedReader(new InputStreamReader(in));

Also, the getSession is wrong as it should be

public Session getSession(String username,

                      String host,

                      int port)

edit

The below code works for me

JSch js = new JSch();

Session s = js.getSession("username", "127.0.0.1", 22);

s.setPassword("password");

Properties config = new Properties();

config.put("StrictHostKeyChecking", "no");

s.setConfig(config);

s.connect();



Channel c = s.openChannel("exec");

ChannelExec ce = (ChannelExec) c;

ce.setCommand("uptime");



InputStream in = ce.getInputStream();

ce.connect();



BufferedReader reader = new BufferedReader(new InputStreamReader(in));

String line;

while ((line = reader.readLine()) != null) {

      System.out.println(line);

}



ce.disconnect();

s.disconnect();



System.out.println("Exit status: " + ce.getExitStatus());

output

 10:26:08 up 149 days, 58 min,  3 users,  load average: 0.61, 0.68, 0.68

Exit status: 0

edited Nov 21 '18 at 1:28

answered Nov 21 '18 at 0:55

Scary Wombat

35.2k32252

edited Nov 21 '18 at 1:28

answered Nov 21 '18 at 0:55

Scary Wombat

35.2k32252

answered Nov 21 '18 at 0:55

Scary Wombat

35.2k32252

answered Nov 21 '18 at 0:55

Scary Wombat

35.2k32252

No work, same behavior.

– E. Betanzos
Nov 21 '18 at 1:14

I have made more edits, also I am assuming that this is replaced with a real command ce.setCommand("command");

– Scary Wombat
Nov 21 '18 at 1:18

I have the getSession call good in my code, like you. That was an translattion error. Yes, I replace command with a real command, and work fine in terminal but in my code no.

– E. Betanzos
Nov 21 '18 at 1:23

see my latest edit

– Scary Wombat
Nov 21 '18 at 1:28

Hmm, Mr Betanzos has gone away?

– Scary Wombat
Nov 21 '18 at 1:48

add a comment |

No work, same behavior.

– E. Betanzos
Nov 21 '18 at 1:14

I have made more edits, also I am assuming that this is replaced with a real command ce.setCommand("command");

– Scary Wombat
Nov 21 '18 at 1:18

I have the getSession call good in my code, like you. That was an translattion error. Yes, I replace command with a real command, and work fine in terminal but in my code no.

– E. Betanzos
Nov 21 '18 at 1:23

see my latest edit

– Scary Wombat
Nov 21 '18 at 1:28

Hmm, Mr Betanzos has gone away?

– Scary Wombat
Nov 21 '18 at 1:48

No work, same behavior.

– E. Betanzos
Nov 21 '18 at 1:14

I have made more edits, also I am assuming that this is replaced with a real command ce.setCommand("command");

– Scary Wombat
Nov 21 '18 at 1:18

I have the getSession call good in my code, like you. That was an translattion error. Yes, I replace command with a real command, and work fine in terminal but in my code no.

– E. Betanzos
Nov 21 '18 at 1:23

see my latest edit

– Scary Wombat
Nov 21 '18 at 1:28

Hmm, Mr Betanzos has gone away?

– Scary Wombat
Nov 21 '18 at 1:48

add a comment |

draft saved

draft discarded

Thanks for contributing an answer to Stack Overflow!

Please be sure to answer the question. Provide details and share your research!

But avoid …

Asking for help, clarification, or responding to other answers.

Making statements based on opinion; back them up with references or personal experience.

To learn more, see our tips on writing great answers.

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Post as a guest

Name

Required, but never shown

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Name

Required, but never shown

Name

Required, but never shown

This page is only for reference, If you need detailed information, please check here

Search This Blog

Ufyukyu