Runtime.exec problem

[boli srivastava]

I have to copy a file using runtime.exec.
I am using the following code , then it is working fine:
String command= "cmd.exe start /c copy"+ " " + "..\\src\\Source.txt" + " " + "..\\src\\destination.txt" ;
System.out.println(command);
Runtime rt = Runtime.getRuntime();
Process proc = rt.exec( command );
int i = proc.waitFor();
the files are copied successfully.
The proc.waitFor() returns zero which is normal termination .

However, when I use this code :

String from ="..\\src\\Source.txt" ;
String to="..\\src\\destination.txt";
String command= "cmd.exe start /c copy" + " " + from + " " + to ;
System.out.println(command);
Runtime rt = Runtime.getRuntime();
Process proc = rt.exec( command );
int i = proc.waitFor();
The files are not copied at all and proc.waitFor() returns 1 which is not normal.

Could you expalin if runtime.exec handles String variables differently.The command is same in both the cases as I am printing it out on console.

[Rob Spoor]

1) UseCodeTags
2) Read the Javaworld article "When Runtime.exec() won't"
3) What is printed to the Process' error stream? Call proc.getErrorStream() and read all data from it.