Runtime.getRuntime().exec("sh export LC_ALL=C") fails!!!!!!!!!!

[Manimekala Velautham]

Hi,

I want to export the LC_ALL variable from Java to set the locale to C instead of other locales.

The command i want to run in HP-UX console is
"export LC_ALL=C"

I tried to execute the above command from a java program, but it did not give any error messages.But the locale is not changed to C.

  
import java.io.DataInputStream;
import java.io.IOException;
 
public class Execute {
 
    public static void main(String[] args) {
           Execute ex = new Execute();
           ex.execute("sh export LC_ALL=C") ;  
    }
    public static String execute(String string) {
           Process p;
           String s = null;
           try {
                p = Runtime.getRuntime().exec(string);
                DataInputStream in = new DataInputStream(p.getInputStream());
                while ( (s=in.readLine())  !=  null){
                      System.out.println(s);
                }
 
                } catch (IOException e) {
                       e.printStackTrace();
                }
                return s;
       }
}

Any input on this problem will greatly help me!!!

[Ernest Friedman-Hill]

Hi,

Welcome to JavaRanch!

The bash command "export X=Y" sets the variable X in the shell where it's called, and further, makes it available to all other processes started from that shell. By executing this command in a shell from Java, you're defining the variable in a shell that executes just this one command and then exits. So whereas the command works, it doesn't do anything!

There's no way for a child process to add something to its parent's environment. Why do you want to do this from a Java program?

[Manimekala Velautham]

Hi
Thanks for your valuable suggestion.

My problem is

I am using JNI for writing logs.
When the locale is set to ja_JP.eucJP, JNI call for writing a syserrlog is printing some japanese characters instead of "Sep" in Timestamp.

If I run a standalone C program to print the date, it is printing in english though the locale is set to ja_JP.eucJP.

When you call the same C function to print the date through JNI, it is printing some junk chars for "Sep".So i want to change the locale "C" from my java program.

I tried Locale.setDefaultLocale(Locale.English)...but still my JNI call is printing some junk chars for "Sep". So i tried by changing the LC_ALL from java program with exec().

Java Code:

    
import java.util.*;
class Logger {
 
     static {
         System.loadLibrary("Logger");
     }
 
     private native void logSysErr();
 
     public static void main(String[] args) {
         Locale.setDefault(Locale.ENGLISH);
         new Logger().logSysErr();
     }
 }

C Code:

    
#include <jni.h>
#include <stdio.h>
#include <time.h>
#include <string.h>
#include <locale.h>
#include <stdlib.h>
#include "Logger.h"
 
JNIEXPORT void JNICALL
Java_Logger_logSysErr(JNIEnv *env, jobject obj)
{
   printf("Logging.....................................\n");
   struct tm *ptr;
   time_t tm;
   char str[90];
 
   tm = time(NULL);
   ptr = localtime(&tm);
   strftime(str ,130 ,  "%b %B %h %d %H:%M:%S",ptr);
   printf("%s   \n",str);
   return;
}

[Ernest Friedman-Hill]

Use the standard C library "setlocale()" function in your native code.

[Manimekala Velautham]

Thanks.
I have tried and it is working fine though the Locale is set to ja_JP.eucJP. But i want to do that from java. Is it possible?...Because, my native methods are shared my many applications.

[Ernest Friedman-Hill]

Originally posted by Manimekala Velauthyam:
Thanks.
I have tried and it is working fine though the Locale is set to ja_JP.eucJP. But i want to do that from java. Is it possible?

Sure. Write another native method!

[Manimekala Velautham]

As per my codebase,writing one more native method will also cause problem,Is there any way to solve this problem in java itself?..

[Ernest Friedman-Hill]

Why would writing another native method cause a problem? Can you create another class called "LocaleSetter" to hold this native method, and just use it in this one application?

But no, I don't believe there's any other way to accomplish what you want.

[Manimekala Velautham]

Hi,

I dropped the idea of doing that in java and I fixed that issue by keeping one more JNI call to set the Locale.

Thank you so much for spending your valuable time in this issue....
Timely Help...Thanks.