Question

I need to come up with a program that generates an xml file like this:

<?xml version="1.0"?>
<xc:XmlCache xmlns:xc="XmlCache" xc:action="Update">
    <xc:XmlCacheArea xc:target="AllSubFields" xc:value="MarketParameters">
        <mp:nickName xmlns:mp="mx.MarketParameters" xc:value="MDS">
            <mp:date xc:value="TODAY">
                <fx:forex xmlns:fx="mx.MarketParameters.Forex">
                    <fxsp:spot xmlns:fxsp="mx.MarketParameters.Forex.Spot">
                        <fxsp:pair type="Fields" value="USD/BRL">
                            <mp:ask xc:type="Field" xc:keyFormat="N">1.890</mp:ask>
                            <mp:bid xc:type="Field" xc:keyFormat="N">1.800</mp:bid>
                        </fxsp:pair>
                    </fxsp:spot>
                </fx:forex>
            </mp:date>
        </mp:nickName>
    </xc:XmlCacheArea>
</xc:XmlCache>

with the values in the nodes mp:ask and mp:bid randomly generated but between two predefined values (1.65 and 1.99).

After the xml is generated in the same directory of the program, the program should run a command in the cmd command line that states:

cachetool.bat -i cacheBody.xml -u REALTIME

where cachetool.bat is an already done bash script that cannot be changed and that is also place in the same directory of the program, and where cacheBody.xml is that previously generated xml.

The trick here is that this should run repeatedly overwriting the xml file with new values each time and then running the command again calling the xml with the new values.

There should be a way to easy interrupt the loop, but besides that, this should run indefinitely.

Note: there isn’t a strict rule to use c or c++, if it isn’t feasible in these languages or if there other ways to do it easily, please feel free to suggest. My initial proposal is in these languages because these are the two that I’m a little used to deal with.

Answer 1

I’m learning how to use javascript for Windows local scripting, so here’s a solution in javascript.

It looks like you don’t really need to generate the XML dynamically, but rather the XML structure is static and only a couple data fields are dynamic. With that in mind, I approached the problem with search-and-replace using a template file.

The template file (template.xml) contains xml content with some variables to search and replace. The format variable format is $RANDOM_X_Y$, where X and Y are the lower and upper bounds for the random number. To help the example, I generated the ask and bid prices slightly differently in the template file:

<?xml version="1.0"?>
<xc:XmlCache xmlns:xc="XmlCache" xc:action="Update">
    <xc:XmlCacheArea xc:target="AllSubFields" xc:value="MarketParameters">
        <mp:nickName xmlns:mp="mx.MarketParameters" xc:value="MDS">
            <mp:date xc:value="TODAY">
                <fx:forex xmlns:fx="mx.MarketParameters.Forex">
                    <fxsp:spot xmlns:fxsp="mx.MarketParameters.Forex.Spot">
                        <fxsp:pair type="Fields" value="USD/BRL">
                            <mp:ask xc:type="Field" xc:keyFormat="N">1.$RANDOM_65_99$0</mp:ask>
                            <mp:bid xc:type="Field" xc:keyFormat="N">1.$RANDOM_650_990$</mp:bid>
                        </fxsp:pair>
                    </fxsp:spot>
                </fx:forex>
            </mp:date>
        </mp:nickName>
    </xc:XmlCacheArea>
</xc:XmlCache>

The javascript file is called replace.js. All versions of Windows should be able to execute it natively without installing any extra components.

if( WScript.Arguments.Count() != 2 || WScript.Arguments.Item(0) == WScript.Arguments.Item(1) )
{
    WScript.Echo("Usage: replace.js <template> <output filename>");
    WScript.Quit();
}

var template_filename = WScript.Arguments.Item(0);
var output_filename = WScript.Arguments.Item(1);
var fso = new ActiveXObject("Scripting.FileSystemObject");
var ForReading = 1;
var file, file_contents, lower, upper;
var var_regex = /\$RANDOM_(\d+)_(\d+)\$/g;

if( fso.FileExists(template_filename) )
{
    file = fso.OpenTextFile(template_filename, ForReading, false);

    file_contents = file.ReadAll().replace(var_regex,
            function(str, lower, upper) {
                return Math.floor(
                    Math.random() * (+upper - +lower + 1)) + +lower;
            });
    file.Close();

    file = fso.CreateTextFile(output_filename, true);
    file.Write(file_contents);
    file.Close();

}
else
{
    WScript.Echo("Template does not exist: " + template_filename);
}

Now to run your scripts indefinitely, just create a batch file called run.bat or whatever and have it run the javascript and batch files in a loop. CTRL–C will exit the script.

@echo off
echo Starting.  Press CTRL-C to exit.
:loop
        replace.js template.xml cacheBody.xml
        cachetool.bat -i cacheBody.xml -u REALTIME
goto loop