Attached are two programs. Compile the C program and the java program. Then run the java program with the C program as the argument. This causes the java program to exec the C program. The user input is then fed to the C program But it never gets to the C program for some reason. Your help would be appreciated.

Rohit

/**************************************************************************/
/*------ test.c ------ C program --- simple program to print uppercase letters to lowercase*/
/**************************************************************************/

#include <stdio.h>
#include <ctype.h>

main() {
 int c;
while((c = getchar()) != EOF) {
putchar(tolower(c));
}
return 0;
}
/**************************************************************************/
/*---- TestExec.java --- Java program for execing C program*/
/* Usage java TestExec c_program_name */
/**************************************************************************/
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.InputStreamReader;
import java.io.BufferedReader;
import java.io.IOException;

public class TestExec {

public static void main(String argv[]) {
Runtime rt = Runtime.getRuntime();
Process proc = null;
BufferedReader in = null;
//DataOutputStream out = null;
PrintWriter out = null;
try {
proc = rt.exec(argv);
if (null == proc) {
System.out.println("Process exec fails");
System.exit(1);
}
in = new BufferedReader(new InputStreamReader(proc.getInputStream()));
out = new PrintWriter(proc.getOutputStream());
if (null == in) {
System.out.println("Input Stream is null");
System.exit(1);
}
if (null == out) {
System.out.println("Output Stream is null");
System.exit(1);
}
}
catch (IOException e) {
System.out.println("Process exec fails: " + e.getMessage());
System.exit(1);
}

String inputStr = null;
String outputStr = null;
DataInputStream systemIn = new DataInputStream(System.in);
System.out.print("Input: ");
try {
inputStr = systemIn.readLine();
while (! inputStr.equals("quit")) {
out.println(inputStr);
out.flush();
outputStr = in.readLine();
System.out.println("Output: " + outputStr);
System.out.print("Input: ");
inputStr = systemIn.readLine();
}
}
catch (IOException ie) {
System.out.println("Interaction Error: " + ie.getMessage());
}
System.out.println("Viola!");
}
}

rohit.valia@Eng 1997-06-09