Persisting MQL5 Expert Advisor Parameters in Shared Binary Files

Summary

This tutorial explains how to preserve Expert Advisor settings across restarts and share them among MetaTrader terminals on the same computer. Its method is to group related, fixed-size values such as numeric trading parameters in a simple MQL5 structure, then write and read that structure as raw binary data in a common file. The discussion covers structure declarations, member access, and the distinction between simple structures and complex ones containing strings, dynamic arrays, pointers, or class objects.

The article walks through saving and restoring example parameters and stresses that the structure used for reading must match the saved field order and types. It also describes checking file handles, considering file size, and closing files after use. The evidence is an implementation tutorial rather than a trading experiment: no strategy results or reliability benchmarks are reported. Raw binary persistence depends on a stable layout, so the guidance is most applicable to carefully controlled parameter records; variable-length data requires additional handling, and the method itself does not address synchronization conflicts when multiple terminals write shared settings.

Key ideas

• A simple structure groups related Expert Advisor parameters into one record for binary file storage.
• Direct binary I/O is suitable for fixed-size fields, while strings and dynamic data need separate handling.
• The read structure must preserve the saved field order and types for values to map correctly.
• Common files allow terminals on the same computer to access persisted settings across sessions.

Tags

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.