change directory in linux with java

tanveer · 03-12-2011, 01:04 AM

Hi all,
I am trying to run the configure command to install a package in linux with Java. Now my workspace location of Eclipse project is /home/user/Workspace/projectx. The source package say zebra is located in /project/test/zebra. Now there is a configure script which I want to run using java and all the outout files will also be created in /project/test/zebra.
Now in Java the code I am using runs the configure command but all the files it creates in current workspace of project which is in /home/user/Workspace/projectx directory.
Now as I tried to do 'cd' command but as it's internal command of linux so it doesn't work and I don't know how to make it work.
Thanks.

Below is the part of the code:

PHP Code:



    private static void createMakefile(String confDir) { 
         
        System.out.println ("Path " + confDir ); 
         
        // Changing to package directory 
        String changeDirectory = "/bin/bash cd " + confDir; 
         
        // setting up command to configure 
        String commandFile = confDir + "/configure" ; 
 
        try { 
            int ch; 
            
            Runtime.getRuntime().exec(changeDirectory); 
             
            Process shellProcess = Runtime.getRuntime().exec(commandFile); 
             
            shellProcess.waitFor(); 
        InputStreamReader myIStreamReader = new 
             InputStreamReader(shellProcess.getInputStream()); 
             while ((ch = myIStreamReader.read()) != -1) { 
             System.out.print((char)ch); 
             } 
             
 
        } catch (IOException anIOException) { 
            System.out.println(anIOException); 
        } 
        catch (InterruptedException e) { 
            System.out.println(e); 
        } 
        catch(Exception e) 
        { 
            e.printStackTrace(); 
         
        } 
 
    }

corp769 · 03-12-2011, 01:13 AM

I'm sure you can use chdir instead.

RASCRanasingha · 03-12-2011, 01:23 AM

Hi Tanveer...

Try Using "/bin/bash -e /bin/cd " instead...

tanveer · 03-12-2011, 01:23 AM

hey thanks I totally forgot this command.
But the problem is it's not recognised in Ubuntu which I am currently working on.
Any other way ?

ntubski · 03-12-2011, 08:06 AM

The current directory is different for every process, so you can't change directory inside one process and expect it to change directory for another. You can use java's ProcessBuilder to set the working directory of an executed command:

Code:

ProcessBuilder pb = new ProcessBuilder(confDir + "/configure");
pb.directory(new File(confDir));
p1 = pb.start()

tanveer · 03-13-2011, 05:19 AM

thanks to all and big thanks to ntubski.
It worked like charm.
I changed the code as follows:

PHP Code:



private static void createMakefile(String confDir) { 
         
        System.out.println ("Path " + confDir ); 
         
        String commandFile =  confDir + "/a.sh" ; 
         
        try { 
            int ch; 
             
            ProcessBuilder pb = new ProcessBuilder(confDir+"/a.sh"); 
            pb.directory(new File(confDir)); 
         
                Process shellProcess = pb.start();  
             
            shellProcess.waitFor(); 
             
            InputStreamReader myIStreamReader = new 
             InputStreamReader(shellProcess.getInputStream()); 
            
             while ((ch = myIStreamReader.read()) != -1) { 
             System.out.print((char)ch); 
             } 
        } catch (IOException anIOException) { 
            System.out.println(anIOException); 
        } catch(Exception e) { 
            e.printStackTrace(); 
         
        } 
 
    }

tanveer · 03-15-2011, 06:34 AM

hello,

Got stuck in one more part and need help.
I am trying to add CFLAGS environment value but its not compiling.

In the below code I just changed this line

PHP Code:



ProcessBuilder pb = new ProcessBuilder(confDir+"/configure");

to this

PHP Code:



ProcessBuilder pb = new ProcessBuilder("CFLAGS=-xyz" + " " + confDir + "/configure");

It's giving me this error:

Code:

Cannot run program "/test/package/configure CFLAGS=-xyz" (in directory "/test/package"): java.io.IOException: error=2, No such file or directory

But it runs from command prompt. I also tried putting the CFLAGS value at then end of configure which also gives same error but that also runs from command prompt.

ntubski · 03-15-2011, 07:13 AM

configure can take environment variable as arguments so you could do:

Code:

ProcessBuilder pb = new ProcessBuilder(confDir + "/configure", "CFLAGS=-xyz");

Or, the direct equivalent of the shell's setting the environment:

Code:

ProcessBuilder pb = new ProcessBuilder(confDir + "/configure");
pb.environment().put("CFLAGS", "-xyz");

tanveer · 03-21-2011, 04:13 PM

Thanks it worked. I should spend some more time on studying documentation of these classes.