CODEWITHSUNDEEP
c
curious
curious

Reputation: 3

Can C program be used without main function?

From a Fortran Code, I intend to run a C code (to read a file) and fetch the read information. The main program is the Fortran code, which uses a function written in C to do the processing. In this C code, is it necessary to run a main function?

Upvotes: 0

Views: 173

Answers (2)

Paul Ogilvie
Paul Ogilvie

Reputation: 25286

If Fortran only calls the C function, then the C code does not need a main() function.

The main() function of C is the program entry point. The system loads the .exe, transfers control to the startup code, which address is mentioned in the .exe file (the startup code is called crt, C run-time start-up). The run-time startup does initialization and then transfers control to the user code. The user code entry point is main().

Since Fortran is the main program, no C run-time start-up is needed and so no main() is needed.

Upvotes: 5

Klas Lindbäck
Klas Lindbäck

Reputation: 33273

No, you don't need a main in your C code. The linker will use the main from the FORTRAN code, or rather, the FORTRAN equivalent of main, when linking your C functions to the FORTRAN program.

Upvotes: 2

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