having problem when compile c file using g++

[liio]

I just wrote a test code file in C-Language like this:

---- test.c ----
#include <stdio.h>

int test(a,b)
int a;
int b;
{
    return a+b;
}

int main()
{
    int a = 2;
    int b = 5;
    int c = test(a,b);
    printf("2+5=%d\n",c);
    return 0;
}

and then I compiled and built with gcc, It works quit well!

-------------
gcc test.c -o test
./test
2+5=7

but when I want to compile with g++, I get following errors:

------------
g++ test.c -o test
test.c:3: error: 'a' was not declared in this scope
test.c:3: error: 'b' was not declared in this scope
test.c:3: error: initializer expression list treated as compound expression
test.c:4: error: expected ',' or ';' before 'int'
test.c:6: error: expected unqualified-id before '{' token
test.c: In function 'int main()':
test.c:14: error: 'test' cannot be used as a function

It seems that g++ doesn't recognize C style function definition.
unfortunately, I have to compile a large ansi-c project with g++, and there are too many c-stlye-defined functions in that project.

Please help!
What should I do to make this through?

[liio]

help!
I go through gcc/g++ man page, but I still cannot solve this.
did I miss something?

[wje_lf]

There's an old style to function definitions in C, and a new style.

The old style can be shown in this example:

int test(a,b)
int a;
int b;
{
    return a+b;
}

The new style:

int test(int a,int b)
{
    return a+b;
}

The new style was introduced when C became ANSI C. ANSI C still allows the old style; C++ does not.

When you compile using g++, you're compiling your source code as though it were written in C++. That's ok for new style functions, but it doesn't allow old style functions.

If you wish to use the g++ command, you'll have to change the old-style functions. If you have quite a few of them, and they're all in a consistent format, you may wish to write a Perl script to change them. But check the output carefully. In fact, use the diff command to focus closely on the changes.

[liio]

yes!
Perl script will solve my problem.
thank you!