Character Strings

Modern Fortran compilers for the Windows operating system support various techniques for passing character string data to a function. The best technique to use when interfacing a Fortran function with IMLPlus is to configure all character string parameters as C strings.

The primary method of the DllFunction class for passing strings is the method NextArgIsConstAnsiString. This method accepts a Java String object as input and passes the string to the DLL function in the following manner:

• The string is passed by reference.
• The string is null-terminated.
• The string consists of single-byte characters.
• The string parameter is assumed to be an input-only read-only parameter. If the DLL function modifies the string, the changes are lost when the function returns because the IMLPlus variable containing the original string is not updated. In any event, the DLL function must not modify the string beyond the zero byte marking its end because memory would become corrupted.

For additional information about passing character strings between IMLPlus and a DLL function, see Passing a Character Matrix to a C Function.