I cannot understand this code

Question

I've been given a C/C++ code that looks like this:

extern int ZEXPORT zipOpenNewFileInZip3 (file, filename, zipfi, extrafield_local)
  zipFile file;
  const char* filename;
  const zip_fileinfo* zipfi;
  const void* extrafield_local;

{

... function body

}

Is declaring the parameters of a function like that possible? I'm getting errors from the compiler (g++).

Thanks in advance.

This may help you : http://stackoverflow.com/questions/1630631/alternate-c-syntax-for-function-declaration-use-cases — VoidPointer, Jul 10 '13 at 10:18
You're not the same guy as asked [this question](http://stackoverflow.com/questions/17566422/what-is-the-weird-usage-in-c-language) are you? Either way, see [these related questions](http://stackoverflow.com/questions/17566422/what-is-the-weird-usage-in-c-language#comment25556566_17566422). — Cody Gray - on strike, Jul 10 '13 at 10:20
WOW! I don't know how many years it is, since I last have seen or used this kind of function declarations. Must be more than 20 Years or so, and now it looks so wrong. :) Those were the days... — Devolus, Jul 10 '13 at 10:25
I've compiled using -std=C89 and it works like a charm. Thank you everyone. — Mangel, Jul 10 '13 at 10:29
`zlib` is full of such declarations, I was also surprised by that quite recently. — riv, Jul 10 '13 at 10:33
I borrowed an old C book some two years ago , it was probably ANSI standard . I read this kind of declaration in that book. Nostalgia :) — 0decimal0, Jul 10 '13 at 10:35

score 2 · Answer 1 · edited May 23 '17 at 11:56

2

This is a very old-school C (pre-ANSI C syntax) way for doing things. I suggest you change it, if you own the code, to

extern int ZEXPORT zipOpenNewFileInZip3 (
  zipFile file,
  const char* filename,
  const zip_fileinfo* zipfi,
  const void* extrafield_local)
...

There are some more details here and here

edited May 23 '17 at 11:56

Community

1
1

answered Jul 10 '13 at 10:19

doctorlove

18,872
2
46
62

score 0 · Answer 2 · answered Jul 10 '13 at 10:32

That is ancient syntax for defining functions in C. It predates the first standardized version of the C language. More importantly, that syntax has never been valid C++. Since you are compiling this code (which is obviously C code) with a C++ compiler, it is failing.

I cannot understand this code

2 Answers2