How to write to other directories in mt4

Is there another method to writing to files in mt4? I need to write out to an outside directory that have be written to and read from more than one mt4 platform. In the help it states that files can only be read and written to in the experts/files directory.

Any help would be greatly appreciated!

That's the MT4 works and there is no way of getting around that in MQL4. There are a number of possibilities outside of MT4 using common scripting and programming languages which basically copy files from experts/files to wherever you want. You could probably find one by searching.

You could always make a DLL which does that.

:nerd:

If you use a dll, you can write to a "shared memory space" from mq4. The shared memory space has to be created with another language, I have done this with c++. Its not easy (at least it wasn't for me) but it can be done. Any number of mt4 platforms can read and write to the shared memory space and share information with each other. I didn't do this with strings, but I'm sure it could be done. I just shared double values stored in an array.

I find this an incredibly bad flaw in mql. I cannot understand why they would allow such a limitation. I was toying with the idea of having an app running that will copy the files to the central location once a change is made, but when there are changes several times a second possibly, this is going to be a nightmare. As for C++, it has been a long time since I have touched it, but do any of you know where I could find the code regarding the shared memory?

Thanks guys for replying!

I had a couple ideas. Is there a way to write to environment variables using mt4, or at least a call that mt4 can make?

Second, since mt4 will write to excel, I was thinking of using an already set up excel sheet that has a secondary sheet that is read in the other platform LINKED to the cell in the first excel platform sheet that will be continuously updated. excel reference is fairly quick, but I think writing to the environment variables would still be quicker.

Any help would be greatly appreciated.

Thanks

You can do that with the Windows API functions - see code base for a sample.

Kenz,
I looked through the code base and I could not find it anywhere. I noticed that you have been involved in this topic before. Were you able to successfully perform this task?

My problem is straight forward. I am only writing one way. One broker platform is the master that is writing the data, and the second broker uses the data. Not sure if that makes this problem easier?

Thanks

Dunno if this is too obviouse but, if the master MT4 is writing data or orders etc, and you want to send this to other MT4, then why not use the same sort EA, Script runnning on the master and just attach it to the slave MT4?

Here is a way to do it:

 

1. Write to the file using standard MT functions.
2. Call an external application that copies the output file to whatever path you specify.
3. Call this application using ShellExecute provided in Windows' Shell32.dll
4. Whenever you need to get new content from the outside file, execute the external application telling it to copy the outside file into to the allowed MT folder.
5. Read from the file using standard MT functions.

Here is how you can copy files to other directories in your MQL script:

http://articles.mql4.com/720
http://codebase.mql4.com/4086

File Operations via WinAPI [ ru ]

http://www.mql4.com/i/print.gif
Introduction


MQL4 is designed in such a way that even incorrectly written programs are unable to mistakenly delete data from the hard disk. The functions used for file reading and writing operations can work in the following directories only (quote):


... large article - everything you ever wanted to know about file i/o ...
#import "kernel32.dll"
.... etc

this script create new file and write string to a file using Win API

Thanks very much guys for the input and help. Looks like there is more than one way to skin this cat, so I will test them and find out which way is the most efficient as I will need to update a file sometimes several times in the duration of a second.

Thanks again!

If that is the case then you're probably better off with sangmane's approach My code copies AND writes/reads the file every time. Unless you're not comfortable with using file functions other than MT's, then sangmane's code should be faster.

if your data is not too long, you can use named pipes, there are some good links out there for use with MT4 . I have used them as a mid level programmer to copy orders between MT4 platforms

I tried, it, and it crashed my platform, besides not writing the file.

Really annoying because I had an optimization running that started 12 hours ago.

create a cshap exe and use the following code
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.Threading;

namespace CopyFiles
{
class Program
{
static void Main(string[] args)
{

Console.Write(Directory.GetCurrentDirectory());
string Src_FOLDER = Directory.GetCurrentDirectory();
const string Dest_FOLDER = @"C:\Tensorflow-Bootcamp-master\Prophet\Data";
do
{
try
{
string[] originalFiles = Directory.GetFiles(Src_FOLDER, "*", SearchOption.AllDirectories);
string test = "";
Array.ForEach(originalFiles, (originalFileLocation) =>
{
FileInfo originalFile = new FileInfo(originalFileLocation);
FileInfo destFile = new FileInfo(originalFileLocation.Replace(Src_FOLDER, Dest_FOLDER));
if (destFile.Exists)
{
test = File.GetLastWriteTime(Src_FOLDER).ToString() + "=?" + File.GetLastWriteTime(Dest_FOLDER);
Console.Write(test);
if (originalFile.Length > destFile.Length || File.GetLastWriteTime(Src_FOLDER) != File.GetLastWriteTime(Dest_FOLDER))
{
originalFile.CopyTo(destFile.FullName, true);
}
}
else
{
Directory.CreateDirectory(destFile.DirectoryName);
originalFile.CopyTo(destFile.FullName, false);
}
});

//Console.Read();
Thread.Sleep(120000);
}
catch(IOException e) {
Console.Write(e);
Thread.Sleep(120000);
}
} while (1 == 1);
}
}
}