64 bit processors and some newb question

Ok, I'm not sure if this should go in newbies or here but I'll go ahead. Just starting to learn C and I got a couple questions.

1) I have an AMD Athlon 64 bit processor. I only have a 32 bit version of windows. From what I understand I will not be able to utilize my 64-bit architecture until windows releases x64, is this true ? (on a side note, will linux be able to utilized my 64 bit processor ?)

2) Any good references on programming with a 64 bit architecture ?

3) From my understanding, x86 processors use little endian byte ordering. Does the AMD, and will this effect writing effeciant 64 bit programs ?

One more question: On a linux command Line, how do I get a programm to accept command line parameters ? like:
#myprog param1 param2

Anyways, I will probably become a regular subscriber to this specific forum, since I am sure I will have more questions :D

This might answer question number two...

http://www.experts-exchange.com/Prog...ing_Platforms/ Intel_Programming/Intel_64Bit_Architecture/ - 47k - 9 Feb 2005

and here's the link to the page I found it on...

http://www.google.ca/search?client=f...=Google+Search
Google Search: programming with a 64 bit architecture

it might provide more resources.

Eg

For easy reference to a variety of programs...


http://directory.google.com/Top/Comp...ing/Languages/

I think this has a strong list.

Windows need Windows XP x64 to use the 64 bits architecture. For Linux, there is 64 bits distructions out there.

I'm not a programmer so I cannot answer the other question! :(

Hi

You need an OS supporting 64bit, if you develop code, you also need a
compiler suitable for 64bit.


64bit processors and OS

Although I mainly work on AMDs Opteron, I made good experience with
the Red Hat Enterprise Linux, which supports most 64bit architectures.
We have it installed on AMD Opteron(tm) Processor 244, AMD Athlon(tm) 64,
Intel(R) Itanium 2 and Intel(R) Xeon(TM) MP(64bit)

There is also a free version of Windows XP Professional x64 Edition[1] available.



64bit processors and compilers

gcc[2] by default creates 64bit code on AMD64-machines. You could generate 32bit
by an -m32 flag. The intel compiler icc[3] usually generates more performant
code on an intel-based machine. You might have to pay for it, but check the licensing
conditions for details.


64bit processor programming

Usually, the correct compiler already produces 64bit code - quite nicely optimised.
You do not have to think about little/big-endian ordering in general.

You can go further in optimisation, but for this you need quite an in-depth
understanding. Check the intel.com[4] and amd.com[5] - pages - an example for
optimisation[6], an example for SSE3[7].


And as per you last question about command line parameter:

Code:

---

...
int main(int argc, char *argv[]){
        int i;

        for (i=0;i<argc;i++) printf("%s\n",argv[i]);
}
...

---

does the job ;)


Cheers


[1] https://microsoft.order-9.com/winxp6...winxp64&id=dl#
[2] http://gcc.gnu.org
[3] http://www.intel.com/software/products/compilers/
[4] http://www.intel.com/cd/ids/develope.../eng/index.htm
[5] https://devcenter.amd.com/
http://devforums.amd.com/index.php?act=idx
[6] http://www.amd.com/us-en/assets/cont...docs/25112.PDF
[7] http://www.intel.com/cd/ids/develope.../eng/66717.htm

whoa! :D Hey guys, thanks.
Extra thanks to sec. Thanks a ton man. :D If I had enought antipoints to assign... :)

Ok, I know it is bad form to post twice in a row, but I couldn't edit my previous post, so here goes...
After my code has accepted the command line parameters, how do I parse the different parameters into seperate char variables ? What I mean is this;

./myprogram param1 param2

now after I accept from argc and argv how do I assign like this;

char param1, param2

char param1()
...code this or that...

char param2()
...code this or that...

...or....

int main(int argc, char *argv[]){
int i;

for (i=0;i<argc;i++) printf("%s\n",argv[i]);
}

after this, to take the integer i and assign the different parameters into different variables

Also, A couple more questions, what are argv and argc ? Why do you assign them into different types of variables ? (char, int)

What does the line:
for (i=0;i<argc;i++) printf("%s\n",argv[i]);
do ?

what does the %s do ?

Sorry for all the questions, it is kinda hard to turn up a (helpful) google. :D

Hi

Maybe you should start reading some basic c tutorials. Two decent ones have been
written by white_scorpion[1]. In the beginner tutorial, you learn about printf,
in the intermediate one %s is explained.

The line

Code:

---

for (i=0;i<argc;i++) printf("%s\n",argv[i]);

---

simply prints the program arguments on the console.

I would not try to achieve too much at once. First, learn to understand
how that little program is doing what it is doing.
char *argv[] are somewhat "advanced" data types (pointers and arrays).

But if you want to convert the first parameter to an integer, try an

Code:

---

  i = atoi(argv[1])

---

If you want to check the second parameter char by char, try an

Code:

---

for (i=0;i<strlen(argv[2]);i++)
      printf("%c",argv[2][i]);

---

Cheers

[1] http://www.antionline.com/search.php...orumchoice=678

hey thanks
I am starting to get this, but I am having some problems (with the different syntaxes I think)

this is what I have:

Code:

---

#include <stdio.h>

int main(void)
{
        char name[15];
        printf("Please enter your name:\n");
        scanf("%s",name);
        if(name == "myname")
        {
                printf("\n%s rocks",name);
        }
        else
        {
                printf("\nHello %s how are you?",name);
        }
        return 0;
}

---

but if I enter myname it still says "hello myname how are you" not "myname rocks" I think it has something to do with the if statement. coulda anyone tell me where I am going wrong ?

Hi dmorgan

The string comparison usually does not work in this way (with exceptions, eg fortran).
I would use

Code:

---

#include<string.h>
(...)
if(strcmp(name,"myname")==0)
(...)

---

Cheers.

ok, heh. Well obviously I have a lot of learning ahead of me :D Thanks for a good point in the right direction. I'll be sure to use some of these resources. Got 'em bookmarked and all :)