How do you check the equality of two byte arrays

[picker]

I'd like to check whether two arrays are exactly equal (same values in indeces) but the following does not seem to work

byte ONE[5];
byte TWO[5];

.....
....

....

...

if (ONE==TWO)
Success;

This seems to check whether the two have the same address and not the actual values. Do I have to run them through a for loop, is there no other way?

[Mark]

Use a loop. If the data is a string, use STRNCMP()

[ckielstra]

or use: memcmp(ONE, TWO, sizeof(ONE));

[Mark]

oops I looked for it in the index of the help file. I didn't see it but do see it listed in the list of standard string functions.

[picker]

It doesn't look like memcmp exists, although it shows in the help file.

[ckielstra]

You'll have to include string.h
It is missing from some of the help files, but it is mentioned in the Aug-2004 pdf-fille.
A tip: Study the supplied header files, a lot of goodies can be found there.

Please note that the length parameter is an int8, so a maximum length of 255 can be compared.

[picker]

Here's the code , what am I missing?

byte Master[8];
byte buffer[8];
...
...
...
...
...
for (i=0;i<8;i++)
Master[i]=buffer[i];

if (memcmp(buffer,master,sizeof(buffer))==0)
Beep_ok();

[ckielstra]

Looks fine to me. What is your problem?

[picker]

No Beep

[ckielstra]

You didn't mention your compiler version, please do so next time.

I compared string.h v3.187 to v3.216 and it seems they fixed a bug somewhere between those versions.
In memcmp(), change

[picker]

Fantastic! Thanks, I'm still running 3.180. I'm too scared to upgrade to a newer version (although I download them) , because everything seems to be working (until I got to memcmp!) and my motto is if its not broken don't fix it...

Thanks for your help ckielstra! Much appreciated...

Regards
Picker

[Guest]

[....]

try visit this link http://ccsinfo.com/forum/viewtopic.php?p=23628&sid=b2a81248802be0631b252a05b677fd18#23628