Host Commands from Java

Question

Hello everyone,
I'm trying to run openVMS host commands via Java using the code listed below, which essentially runs the following host commands, each in turn:
terry :== "hello"
sho sym terry
sho log robin4
I've tried a few other commands as well, but the ones which assign variables (such as the terry example above), never work, either producing no output as in the example above, or if I did
define/group "hello" terry
would produce:
DCL-W-NOCOMD, no command on line - reenter with alphabetic first character
So commands that don't print anything to the screen are the ones that are causing problems (they're just setting variables or what not).
Does anyone have any ideas as to how to get these commands working via java? I really don't know what to think..I've tried checking the format of the commands I'm trying to do, and it's not down to that - the host command I'm running is right and works if done directly.
Please help! Thank you so much in advance.
Robin
import java.io.*;
public class Host {
public static void executeCommand(String command) {
String s = "hello";
String s2 = "sho log robin4";
String s3 = "assign/system "+command+"hello"+command+" robin5";
try {
String[] finalCommand;
System.out.println(System.getProperty("os.name"));
finalCommand = new String[3];
finalCommand[0] = "terry :== \"hello\"";
finalCommand[1] = "sho sym terry";
finalCommand[2] = s2;
for(int i = 0;i< finalCommand.length; i++){
// Execute the command...
final Process pr = Runtime.getRuntime().exec(finalCommand);
// Capture output from STDOUT...
BufferedReader br_in = null;
try {
br_in = new BufferedReader(new InputStreamReader(pr.getInputStream()));
String buff = null;
while ((buff = br_in.readLine()) != null) {
System.out.println("stdout: " + buff);
try {Thread.sleep(100); } catch(Exception e) {}
br_in.close();
} catch (IOException ioe) {
System.out.println("Error printing process output.");
ioe.printStackTrace();
} finally {
try {
br_in.close();
} catch (Exception ex) {}
// Capture output from STDERR...
BufferedReader br_err = null;
try {
br_err = new BufferedReader(new InputStreamReader(pr.getErrorStream()));
String buff = null;
while ((buff = br_err.readLine()) != null) {
System.out.println("stderr: " + buff);
try {Thread.sleep(100); } catch(Exception e) {}
br_err.close();
} catch (IOException ioe) {
System.out.println("Error printing execution errors.");
ioe.printStackTrace();
} finally {
try {
br_err.close();
} catch (Exception ex) {}
catch (Exception ex) {
System.out.println(ex.getLocalizedMessage());

Answer 1

User_resU wrote:
Hello everyone,
I'm trying to run openVMS host commands via Java using the code listed below, which essentially runs the following host commands, each in turn:
terry :== "hello"
sho sym terry
sho log robin4
1. Presumably this represents some sort of character user interface (CUI) which is console based.
finalCommand = new String[3];
finalCommand[0] = "terry :== \"hello\"";
finalCommand[1] = "sho sym terry";
finalCommand[2] = s2;
final Process pr = Runtime.getRuntime().exec(finalCommand);
2. This represents an executable to which you are passing command line arguments.
This isn't a java problem because 1 and 2 are not even close to being the same.
Java won't do anything that you cannot get the application to do itself.
Your choices:
1. Find a way to run the app such that it takes commands from a file. You put the commands in a file and pass that to exec()
2. Find a way that use stdio (the CUI might represent that but there is no guarantee.) You then use exec() to start the app then use the IO streams to pass the commands to it.
Notice that my choices do not include an option for passing as command line parameters because I am almost certain that it does not exist.