string concatenation

[Marlene Miller]

What is the output for this code?

class Test {
   public static void main(String[] args) {
      for (int i = 0; i < args.length; i++) {
         System.out.println("i" + i + ":" + args[i]);
      if (args.length < 1)
         System.out.println("Empty");
      }
   }
}

Now try it with this: java Test * ??

[Monisha Talwar]

My guess would be you should see
0:*
Are you getting something different?

[Eric Waite]

I am using cygwin shell on windows and it wildcard sends in all filenames. doh!
Any other String works correctly.
Not really sure how to command-line pass in a character that is also a wildcard in the shell.

[Junilu Lacar]

You'll need to run it with
java Test "*" to get the 0:* output.
Not too sure which one but either the Java runtime or OS (I'm running Windows, don't know if this is true for other OS's though) picks up on the wildcard character * in the command line first and takes it to mean that you want to pass all filenames as parameters.
This has been discussed before so you could try to do a search to find more about it.

[Thomas Paul]

It is a problem in Windows, Unix, and Linux. You must put quotes around the *.
It is not a Java Problem since the OS changes it before Java ever sees it. It happens in C programs too!
[ April 03, 2003: Message edited by: Thomas Paul ]

[Barry Gaunt]

It's called filename globbing, if I remember correctly. Just a feature of UNIX like shells.

[Marlene Miller]

Thank you Monisha, Eric, Junila, Thomas, Barry.
I don't know about you, but in this study group I get so focused on syntax, I forget about real-world effects.

[Rajeshwari Natarajan]

* is a wildcard for searching for filenames. So when u use it in the command line args[0] will return the name of the first file in the directory in which ur class file resides.