C / C++ / MFC

CPallini26-Mar-10 3:24

26-Mar-10 3:24

I hope your brilliant brain will eventually overcome the 'skip blanks and tabs' daunting trouble. Laugh | :laugh:

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

Covean26-Mar-10 3:29

Covean

26-Mar-10 3:29

Thanks (oh my master Poke tongue | ;-P

) this saved my day! Laugh | :laugh:

Greetings
Covean

tom groezer26-Mar-10 3:55

tom groezer

26-Mar-10 3:55

thanks my optimistic philospher.
you work full time on this board and are getting paid for the sh*t u speak.

jeron126-Mar-10 4:27

jeron1

26-Mar-10 4:27

If you spent half the time working on your problem than you do hurling insults, you probably would answered your own question hours ago.

jeron126-Mar-10 3:55

jeron1

26-Mar-10 3:55

Tim Craig26-Mar-10 8:28

Tim Craig

26-Mar-10 8:28

tom groezer wrote:
I need a urgent fix and dont want to travel googling.

It doesn't get much faster than Googling so get used to it. If you had a clue, you'd have had your answer before you could post here.

You measure democracy by the freedom it gives its dissidents, not the freedom it gives its assimilated conformists.

Iain Clarke, Warrior Programmer

Iain Clarke, Warrior Programmer26-Mar-10 4:37

26-Mar-10 4:37

I'm not quite sure what you've done to annoy CPallini... but he has my trust, so I assume you deserve the long flamewar above this post.

But *I'm* in a good mood...

I would not use the sscanf function at all for this.

One, the tabs / spaces are delimiters. In which case, read a line of text in, then use your favourite string classes Find function to get the next whitespace. Then parse the next up to that point. Delete the text you've parsed, and repeat.

OK, once you've broken the long line into stringlets, then you can use sscanf if you like!

Good luck,

Iain.

I have now moved to Sweden for love (awwww).

CPallini26-Mar-10 9:25

26-Mar-10 9:25

I love you, man (expecially with the warrior outfit). Smile | :)

Tim Craig26-Mar-10 18:21

Tim Craig

26-Mar-10 18:21

CPallini wrote:
expecially with the warrior outfit

Since he moved to Sweden, does that involve a big helmet with horns? Laugh | :laugh:

And yes, I know the Vikings didn't actually wear those but they're cool anyhow. Cool | :cool:

You measure democracy by the freedom it gives its dissidents, not the freedom it gives its assimilated conformists.

CPallini27-Mar-10 5:30

27-Mar-10 5:30

I think you missed something [^]...
Big Grin | :-D

Tim Craig27-Mar-10 8:13

Tim Craig

27-Mar-10 8:13

Guess so!

I don't usually check the profiles of people I'm familiar with. Guess we'd better send the word out that a raiding party is on the way. Laugh | :laugh:

You measure democracy by the freedom it gives its dissidents, not the freedom it gives its assimilated conformists.

David Crow26-Mar-10 4:47

David Crow

26-Mar-10 4:47

After your tirade to other professionals here, you surely do not deserve any help.

tom groezer wrote:
I need to parse a file...
I'm using sscanf function.

Which means you are using the wrong tool for the job. fscanf() would be used to parse the file, while sscanf() would be used to parse a string read from the file. There is a subtle but big difference. Learn that difference and you'll save yourself many bouts with foot-in-mouth disease.

tom groezer wrote:
How do I ensure that I skip the spaces and tabs which could be in randon number.

Is it really that hard to find something like:

char *str = "I  really\tdo \t not  deserve    any\t  help";
char s1[8], s2[8], s3[8], s4[8], s5[8], s6[8], s7[8];
sscanf(str, "%s %s %s %s %s %s %s", s1, s2, s3, s4, s5, s6, s7);

"One man's wage rise is another man's price increase." - Harold Wilson

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

"Man who follows car will be exhausted." - Confucius

Adler32 Algorithm Doubts

rupeshkp72825-Mar-10 23:42

rupeshkp728

25-Mar-10 23:42

I am writing a adler32 code to compute the adler32 checksum of a string.
On the net I came across various sample codes:
I did not understand some code entirely as <b>it has additional code</b> marked in bold below apart from the basic implementation of the adler32 logic.
I did not understand the addional part as to what is is doing.
Can anybody experienced with adler32 give some hint on it?

The various sample codes are:

//---------------------------------------------------------------------
// WIKI
I understood this code as its the basic implementation of the adler32 logic.
So no doubts in this.

/* Loop over each byte of data, in order */
for (size_t index = 0; index < blen; ++index)
{
a = (a + buff[index]) % BASE;
b = (b + a) % BASE;
}

wweak_cs = (b << 16) | a;
//---------------------------------------------------------------------
// RSYNC
I did not understand some code marked in bold below.
{
#define CHAR_OFFSET 0
char *buf = buff;
int len = blen;
int index = 0;
UINT32 s1, s2;

s1 = s2 = 0;
for (index = 0; index < (len-4); index+=4)
{
s2 += 4*(s1 + buf[index]) + 3*buf[index+1] + 2*buf[index+2] + buf[index+3] + 10*CHAR_OFFSET;
s1 += (buf[index+0] + buf[index+1] + buf[index+2] + buf[index+3] + 4*CHAR_OFFSET);
}
for (; index < len; index++)
{
s1 += (buf[index]+CHAR_OFFSET); s2 += s1;
}
rweak_cs = (s1 & 0xffff) + (s2 << 16);
weak_cs = rweak_cs;
}
//---------------------------------------------------------------------
// sharpdevelop
I did not understand some code marked in bold below.

{
char *buf = buff;
int len = blen;
sweak_cs = 1;
int s1 = sweak_cs & 0xFFFF;
int s2 = sweak_cs >> 16 & 0xFFFF;
int index =0;

while (len > 0)
{
int n = 3800;
if (n > len)
{
n = len;
}
len -= n;
while (--n >= 0)
{
s1 = s1 + (int)(buf[index++] & 0xFF);
s2 = s2 + s1;
}
s1 %= BASE;
s2 %= BASE;
}

sweak_cs = (s2 << 16) | s1;
weak_cs = sweak_cs;
}
//---------------------------------------------------------------------
//altivec
I did not understand some code marked in bold below.

{
#define NMAX 5552 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
#define DO1(buf,i) {s1 += buf[i]; s2 += s1;}
#define DO2(buf,i) DO1(buf,i); DO1(buf,i+1);
#define DO4(buf,i) DO2(buf,i); DO2(buf,i+2);
#define DO8(buf,i) DO4(buf,i); DO4(buf,i+4);
#define DO16(buf) DO8(buf,0); DO8(buf,8);
# define MOD(a) a %= BASE

char *buf = buff;
int len = blen;
aweak_cs = 1;
unsigned long s1 = aweak_cs & 0xffff;
unsigned long s2 = (aweak_cs >> 16) & 0xffff;
int k;
while (len > 0)
{
k = len < NMAX ? (int)len : NMAX;
len -= k;
while (k >= 16)
{
DO16(buf);
buf += 16;
k -= 16;
}
if (k != 0)
{
do
{
s1 += *buf++;
s2 += s1;
} while (--k);
}
MOD(s1);
MOD(s2);
}

aweak_cs = (s2 << 16) | s1;
weak_cs = aweak_cs;
}

Can anybody clear the doubts?

CPallini26-Mar-10 1:09

26-Mar-10 1:09

Why do you need the 'additional code' can you just use the basic algorithm?
Smile | :)

tom groezer26-Mar-10 1:38

tom groezer

26-Mar-10 1:38

Here also Mr Palini is gracing the posts by his immmaculate understanding of software. Trying to highlack things. Boss come on earth else you will thump down.

CPallini26-Mar-10 1:44

26-Mar-10 1:44

tom groezer wrote:
Here also Mr Palini is gracing the posts by his immmaculate understanding of software.

Wow, that's actually nice! Smile | :)

Well, of course you missed the point of my post.