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SYSTEM_CALL Subroutines

A SYSTEM_CALL is a special type of subroutine that is defined in a separate program file called a LIB (library) file with a PROGRAM_NAME entry matching the subroutine name, as shown below:

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PROGRAM_NAME = 'COSX'

DEFINE_CALL 'COSX' (FLOAT X)
{
    (* body of subroutine *)
}

The compiler generates a call to the subroutine in the library file and automatically includes the library file for compilation. System Calls are resolved automatically at compile time without requiring an INCLUDE instruction to include the System Call source file.

To invoke a System Call, use the SYSTEM_CALL keyword followed by the Program Name defined in the LIB file, in single quotes and any calling parameters, as shown below:

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SYSTEM_CALL 'COSX' (45)

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