relative pointers on Unix

Applications Programming
1

Hi all:
We're porting lot of C code from Windows to Unix.
In Windows we're using relative pointers (with the _based keyword) to
access some structures placed on shared memory. We would need
something like the Microsoft's _based keyword for unix.
Does something similar exist in Unix? If not, is there any other way to get the same functionality as _based on windows.

See the link below to know more about the _based keyword on windows.
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vccore98/html/\_langref___based.asp

Many Thanks,
Rahul

2

Microsoft is bad about C standards conformance.

This is a relative pointer, a pointer that is set to a base value and then offset by a fixed "distance"

int foo()
{
    int a[100]={0};     
    int *base=a;          
    int i=0;              
    for(i=0;i<100;i++)    
    {                     
         int q=*(base+i);   /* base+i is the relative pointer */
         printf("%d\n",q);
    }                     
    return 0;
}

This is also a relative pointer:

     int foo( int *a)
     {
           int i=0;
           for(i=0;i<100;i++)
           {
               printf("%d\n", a); /* a is also a relative pointer */
           }
           return 0;
      }

The a [i]thing is array notation, but it is an offset against a base. They are all compiled into the same machine code.

3

I wrote a small C script in Note Pad and I want to know can it be executed like a shell to get results.

If not

Do I need to purchase RedHat Linus or SUSE Linus with a compliler on it for my home computer or can I get it Free.

Novice, looking for Big Help and Understandiong from you in trying to get started with writing scripts for C and C++.

Thank you in advance for your understanding of a beginner and advise.

Lost, Alone, and COnfused about C Scripts

SLP

4

C is not a scripting language.
about your question, there're a lot of zero-price GNU/Linux distros around the www. i can suggest Gentoo which is distrubuted under the GPL, but it's installation is done by using standard unix tools (well, mostly). if you're not familiar with unix and insist on a gui-installer, you can try Fedora Core or better yet, google for GNU/Linux distros.