System and method for achieving specific behaviors by intercepting file access calls in a mainframe rehosting platform

A method for achieving specific behaviors in a rehosted mainframe application executing on a microprocessor, the method comprising:

• providing an application runtime in a mainframe rehosting platform for executing a mainframe application migrated from a mainframe computer;
• providing a custom file handler in the application runtime, wherein the custom file handler comprises a plurality of custom file operation application programming interfaces (APIs), wherein each custom file operation API is configured to perform a specific behavior, wherein the custom file handler is compiled in a particular format and placed on a runtime library path of the application runtime, wherein an environmental variable representing the runtime library path is exported for use by the rehosted mainframe application to detect an existence of the custom file handler;
• intercepting, using the custom file handler, a file access call from the mainframe application migrated from a mainframe computer;
• and
• using a corresponding custom file operation API in the custom file handler to process the intercepted file access call.

A non-transitory computer readable storage medium, including instructions stored thereon which when read and executed by one or more computers cause the one or more computers to perform a method comprising:

• providing an application runtime in a mainframe rehosting platform for executing a mainframe application migrated from a mainframe computer;
• providing a custom file handler in the application runtime, wherein the custom file handler comprises a plurality of custom file operation application programming interfaces (APIs), wherein each custom file operation API is configured to perform a specific behavior, wherein the custom file handler is compiled in a particular format and placed on a runtime library path of the application runtime, wherein an environmental variable representing the runtime library path is exported for use by the rehosted mainframe application to detect an existence of the custom file handler;
• intercepting, using the custom file handler, a file access call from the mainframe application migrated from a mainframe computer;
• and
• using a corresponding custom file operation API in the custom file handler to process the intercepted file access call.