Thread: command line asterisk converted to list

I am writing a program to take 3 command line arguments and perform simple arithmetic. The second argument is the operator, and the first and third are operands. They all work fine except for the asterisk. It is converted to a list of files in the current directory. I am working under the command line in Windows XP. Does anybody know of a way to fix this problem and have an asterisk just represent an asterisk? Thanks.

Code:

#include <iostream>
using namespace std;

int main(int argc, char* argv[])
{
    for (int i = 0; i < argc; i++)
    {
        cout << argv[i] << endl;
    }
    return 0;
}

/*
Test Run:
c:\test>test.exe 5 * 8
test.exe
5
test.cpp
test.exe
8

where test folder contains test.cpp and test.exe
*/

Strange. When I run that program (on XP) from command prompt this is what I get:

Code:

> test 5 * 8
test
5
*
8

Which is what I would expect

> test.exe "5 * 8"

> I am working under the command line in Windows XP
But which compiler?

Wildcard expansion of the command line (or globbing) can be turned on or off at various points, depending on your shell / OS / compiler ....

Well actually I discovered the problem working in Java using the most current javac compiler. But I also tested this in the most current version of Dev-Cpp (4.9.9.2). Might there be a way to disable it at the command line? Or is it something I'd have to write special code to handle?

I think it's a feature of the shell, not of your program.

If that's the case, then I have two questions:
1. Why does it do the same thing when I run my java program from the IDE and just set the command line parameters? It isn't using the command line shell is it?
2. How can I change the behavior of the shell? Or is it not possible?

1. Why does it do the same thing when I run my java program from the IDE and just set the command line parameters? It isn't using the command line shell is it?

What I mean is, whenever a program is launched, * is expanded. Try *

Code:

system("program *");

[edit] Yes, it does use the shell. Every time you evoke a program, you use the shell. (At least that's what I've always thought.) [/edit]

2. How can I change the behavior of the shell? Or is it not possible?

I don't know much about that.

But it must be possible: Try this:

Code:

C:\>echo *

On my non-windows XP computer that echos "*".

I would suggest making the program take as arguments "5*4", with no spaces, or else read input from stdin; you could provide an equation like this:

Code:

C:\>echo 5+4 > program

[edit=2] * Of course, you shouldn't do this. [/edit]

Well it sounds like this is more of a problem than I thought it was. Right now I'm not worried about hacking together a solution just so that my simple arithmetic problem will work without me needing to use quotations around an asterisk. That's much simpler. Thank you for your help, I have learned a lot from this.

5*3 still won't work if there's a file called 5foo3 in the current directory. Then it'll expand just like any other pattern.

To be really safe, put a character in the argument, such as ':', that can't exist in a file. (Of course, it can exist in a Linux filename, but under Linux you'd just use single quotes around the parameter, and the shell won't do globbing. That's what it's called; globbing.)

[edit]
(From signature)

I like hiding things

What you should do is look at the source for a typical CBoard page and find out what the background colour is, and set that text to that.

Sorry for spoiling your signature.
[/edit]

I hate you!

EDIT: Sorry for the double bump! My anger flamed the passionate hatrid I now feel towards dwks! :P

it used to be 'PM me if you see this', then 'Gone unnoticed for weeks', then 'Gone unnoticed for months', and at the start there was no hidden message there.

EDIT 2: I like magenta. Changed it

"Hiding in plain sight." That's what you should make it.