Searching Buffers and comparing to characters NOT IN RAM

[Gabriel]

hello all,

I'm working on a gsm project but I am having some issues on how to
get data from a buffer that gets filled on my ISR.

Its for a GSM project but not a GSM question, I got that part DOWN! haha.

The problem is something like this:

Buffer[50]={'a','b','c',.....'s','t','r','i','n','g',....'z'}
//once i get all my data my buffer is something like that...


I want to check if "string" is somewhere inside my buffer.
I can check for individual characters with a for loop and one thousand nested "IF" statements... since I am looking for the characters "string" in that precise order but that sucks. Doesn't seem too efficient
and I'm not going to be able to reuse my search function to get other strings.

Wanted to see if anyone had a nice method of doing this. My ideal method and additional issue are as follows.

ALSO, since I have a little RAM issue, I was wondering if there was a
way have a list of characters on the program code, NOT IN RAM, and
be able to compare that list or lists to my buffer...
It would be nice if this list (more like a table) could be searched using a counter.

So that I could feed my buffer and the list/table to a for loop
with the appropriate counter values and only compare a set of characters
one by one.

So I would have something like this:

(pseudo / semi real / imaginary code)...

[mkuang]

You can use the strstr() function which comes with <string.h>. The function returns a pointer to the first occurence of the string. From Barnett and Cox's book an example code snippet looks like:

[mskala]

This is already available. Use strstr(), or if more complicated, strtok().

Note that CCS probably requires both to be in RAM, not ROM.

Mark S.

[Gabriel]

mkuang:

that is sweet, but as far as i can see,

i have to have the string im looking for on another string/array
in RAM....which is what i am trying to avoid...

i liked your suggestion... i think if all else fails, ill take this one...
seems pretty good, exept for the RAM part...

(im not trying to shoot down your suggestion because its not exactly what im looking for.... i do like it, and probably will have to use it... just wanted to clarify that im not being an ungratefull Bi..h*)

thanks for your help...


g
_________________
CCS PCM 5.078 & CCS PCH 5.093

[mkuang]

In my code snippet if you declare:

[Gabriel]

Mkuang,

hold the phone. hahaha... if you declare something as

Const char str[]="ABC",

its on rom, as in the program memory? SWEET... (is it?)

can i search through this const array using a counter

kinda like :

Const char str[]="ABC";

if(str[1]=='B';
do somthing....

... if the above is true... my problem is solved...

is it?

G
_________________
CCS PCM 5.078 & CCS PCH 5.093

[mkuang]

Unfortunately your buffer[50] has to be in RAM since the values it is holding can change. What is NOT changing presumably are the characters that you know you are looking for. i think you stored these values in the array called Table. These are the characters you can place in ROM. If you look at the hex file you actually see these constants in there if you ever make a test program.

[Gabriel]

yeah yeah i know that my buffer[50] will be on ram..

i need it there....


the issue is with the strings that i want to look for...
as long as i can keep those in ROM and can search the "table" using a counter i am set...

is my example on my previous post true?

g
_________________
CCS PCM 5.078 & CCS PCH 5.093

[mkuang]

[Gabriel]

mkuang... i think i love you...

hahahaha


thank you

g
_________________
CCS PCM 5.078 & CCS PCH 5.093

[mskala]

Sorry, this will fail. CCS will not allow the argument to be a pointer to constant. You will need to copy to RAM.

[Gabriel]

...damn

so close.....

further suggestions?

g
_________________
CCS PCM 5.078 & CCS PCH 5.093

[mkuang]

[Gabriel]

wait wait wait


but will this work:

const char strA[]="ABC";

if(strA[1]=='B')
do somthing?
_________________
CCS PCM 5.078 & CCS PCH 5.093

[treitmey]

In the end, all i've ever seen has been..
keep them all in ROM.
copy ROM entry for item you want to RAM.
compare in RAM.