Re: Why does this only work when I am running a shellscript

I have the following code:
    private static void doCommand(final String cmd) throws IOException {
        Process p;
        Scanner sc;

        System.out.println("#" + cmd + "#");
        p = Runtime.getRuntime().exec(cmd);
        sc = new Scanner(p.getInputStream());
        while (sc.hasNext()) {
            System.out.println(sc.nextLine());
        }
    }

When I call s shellscript like:
    doCommand("createQuote.sh citation");

It works as I would expect. When I use something like:
    /usr/bin/convert ?

It hangs. It is not the command, because if I execute the command I
print in the shell directly, there is no problem.

So what is happening here?