Command-line Arguent Examples

Python:

Let's remind ourselves by running this.

from sys import argv
print(argv)
print(type(argv))

The object argv is a list of strings. The first element in the list is the name of the program.

unix> python commando.py
['commando.py']
<class 'list'>

Now let's have the user enter some command-line arguments.

unix> python commando.py cow pig horse elephant
['commando.py', 'cow', 'pig', 'horse', 'elephant']
<class 'list'>

The rest of the items are strings typed in by the user of the program at the command line.

Java:

We do an import of the class Arrays here becuse Java arrays do not know how to print themselves nicely

The call Arrays.toString will make this happen.

import java.util.Arrays;
public class Commando
{
    public static void main(String[] args)
    {
        System.out.println(Arrays.toString(args));
    }
}

unix> javac Commando
unix> java Commando
[]
unix> java Commando pizza hoagie hamburger
[pizza, hoagie, hamburger]

Note that the array args does not include the name of the program.

         These guys can reach
         across the top        -|G
                               -|R
                               -|E
                               -|A
        instance land          -|S   static land
            state variables    -|E       static data (ORIGIN)
            non-static methods -|        static methods
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