How to compile an MQL4 file with a command-line tool?

Question

Now I am compiling my MetaTrader .mq4 files to .ex4 files with MetaEditor.

But my .mq4 files are generated by a Java-process, and I would like to automate the compilation process.

Is there a command-line compiler tool I could call programmatically?

Answer 1

To compile a source code file from a command line, you can use MetaEditor for that. For example:

metaeditor.exe /compile:"C:\Program Files\Platform\MQL5\Scripts\myscript.mq5"

^{For 64-bit use metaeditor64.exe instead.}

In Linux/macOS, this can be achieved using Wine, e.g.:

wine metaeditor.exe /compile:"MQL4/Experts/MACD Sample.mq4"

For mass compilation, you can specify folder, like:

metaeditor.exe" /compile:"MQL5\Scripts"

To specify custom MQL5/MQL4 folder with include files, you can use /inc parameter, for example:

metaeditor.exe /compile:"./Scripts" /inc:"C:\Program Files\TradingPlatform 2\MQL5"

For additional information about the compilation process, you can use /log:

metaeditor.exe /compile:"C:\Program Files\Platform\MQL5\Scripts\myscript.mq5" /log 

^{To check for the syntax only, add extra /s.}

If the compilation fails, the MQL4.log file would be created in the platform folder with the relevant details. It's going to be in UTF-16 format, so you may need a special tool for it (such as Vim, Ruby, findstr or rg).

To specify the custom compilation log file, use /log:file.log parameter, e.g.

metaeditor.exe /log:errors.log /compile:.

Note: Display to the standard output is not supported (although on Linux you can use: /log:CON).

For more information, check: Compilation from the Command Line

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Some time ago you could download the compiler of MQL4/MQL5 programs that runs separately from MetaEditor — MQL.exe. It was distributed separately from the terminal and you could download it at the following addresses:

https://download.mql5.com/cdn/web/metaquotes.software.corp/mt5/mql.exe

https://download.mql5.com/cdn/web/metaquotes.software.corp/mt5/mql64.exe

Usage (as per MQL4/MQL5 Compiler build 1162 from 02 Jul 2015):

mql.exe [<flags>] filename.mq5
        /mql5     - compile mql5 source
        /mql4     - compile mql4 source
        /s        - syntax check only
        /i:<path> - set working directory
        /o        - use code optimizer

However the standalone compiler was intentionally removed, so now links point to the installer in favor of MetaEditor.

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Much older version of MetaTrader prior to build 600 had metalang.exe included with the platform.

However in build 616, MetaQuotes intentionally has removed the compiler (mql.exe/mql64.exe) from the standard MetaTrader installation.

This means if you upgrade your MT platform (>616), the compiler executable will be removed.