On (24 Nov 94) Paul Edwards wrote to Rafael Solomon...



 ac>> int main(void)



 RS> I have only started programming in C so I haven't used that can you

 RS> tell me the advantages of that compared to "void main()"



 PE> It's not a matter of advantages, it's a matter of only one way

 PE> is correct, and that's int main(void).  The ISO C standard only

 PE> says "int main(void)" and "int main(int argc, char
**argv)" are

 PE> valid.  If your compiler supports a NON-STANDARD extension,

 PE> that's it's problem.



 PE> You should always exit main() with a return (0) [or a similar

 PE> strategy] in order to let the operating system know that it

 PE> finished OK.  Your program did finish OK, didn't it?  Failure

 PE> to set a return code will cause the MSDOS errorlevel to be

 PE> set to a random value, assuming you are using MSDOS.  That is

 PE> not what a good program does.



Hi Rafael



 Don't mind Paul, he'd burn all Borland users at the steak (sic)

if he could.



 We fought about this a while ago, and the arguments that convinced

me that int main() was better than void main() ran something like:



1. int main() returns an int value to the calling program /

operating system, and you (the programmer) are in control of what

that return value is. You may say (as I did) that you have no use

for such a feature, but one day you may write a non-trivial program

that other people will use. You cannot control how those other

users will use your program, and there's a good chance that some of

them will be looking for a return value to detect fatal problems

(missing input files, for instance). Using void main(), and/or

failing to return a predictable error value, can annoy these users

enough for them to drop your program. Using int main(), and

mentioning in your docs just what your return values mean, can be

quite helpful to an end user.



2. Using int main() and returning an error value is quite easy to

do, and helps you think about how and why you are exiting your

program, so why not get into the habit of doing it?



Cheers



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