data structer in programming?

 data structer in programming?

how i can implement variable length data base ( or data storage structure)in keil C programe?

 RE: data structer in programming?

linked list, B-tree, heap etc...

 RE: data structer in programming?

Ring-buffer?

 RE: data structer in programming?

binary tree...?

 RE: data structer in programming?

hash table...?

 RE: data structer in programming?

yes , i know that but how would i implementing in keil C51, any sample code, which give me idea

 RE: data structer in programming?

We can't spend a week trying to pump random source code into this thread.

You haven't spent any time at all trying to tell us your needs, and exactly what access and allocation patterns you will have. You will have to take the lead, by showing that this is important to you and supply the best information you can.

 RE: data structer in programming?

i have another question shall we implement tree data structure in keil c51? if yes, then what size of memory required for data storage

 RE: data structer in programming?

"what size of memory required for data storage[?]"

Are you trolling? Exactly how do you expect anyone here to be able to say how much memory _you_ would need for _your_ application? Remember that you haven't told us anything about the application...

 RE: data structer in programming?

oh! sorry, i m designing C8051F020 based collage student data logger in which i m entering whole details of student (student database) & used for smart card system.

 RE: data structer in programming?

Then I would suggest something simple, like a ring buffer. Easy to throw away old entries when new data arrives and you can't read out the current log.

You will have to compute yourself your needs.

How large user ID number for each log entry?
How much data for the time stamp? Depends on how long time you must be able to span, and your required resolution.
How much data for additional information, such as ok/fail on PIN code entering etc.

But your project includes thinking about these kind of things. You will have to make a design. You will then have to review it. Then you will have to modify any weak spots you find. Then you implement and debug.

 OH, NO

But your project includes thinking

 then what size of memory required for data storage

I think Parkinson's Law applies here...

 RE: data structer in programming?

please tell me what is data structer

 RE: please tell me what is data structer?

Almost certainly a mis-spelling of "data structure"?

 how would i implementing in keil C51

Think about how you implement them "normally", then check if C51 poses any restrictions on that - RTFM: http://www.keil.com/support/man/docs/c51/

You also need to be aware of the limitations of the underlying architecture - why do you actually want to do this on an 8051??

 RE: how would i implementing in keil C51

the 8052 Max RAM is 64K. If you need more than that you need external storage. You can Use Banking to increase it, but it adds a lot of complexity. Serial memory or SD Cards are better since you will not be time critical (see how a little info from you changes the answers you get)
If you are looking for malloc(). It is there but you need to configure it. Also it is a very poor choice for a small embedded system.

 why variable?

how i can implement variable length data base

you will need memory space for the max size, why not just allocate that or "all available memory"?

Erik