Thread: !@#&*!!# strstr()

Hello everyone.

Right now I am cursing the C language.

Why does it have to be so buggy?

Well here's my problem:

I have an array of pointers. The pointers point to strings. Printing the array yields the proper output.

I now want to SEARCH the array for certain strings.

If a match occurs, print certain strings in the array.

Simple, right?

Well, not so simple, because when I search for KNOWN strings(or rather their pointers) in the array, sometimes it finds them, sometimes not! Yet it should every time because I've printed the arrays values, and everything's in it's place!!

So why is "strstr()" being so picky?



Let's look at the code.

But first, let me show you a sample array printout:
___________________________________
line_ptrs[0] = "john ";
line_ptrs[1] = "peters ";
line_ptrs[2] = "texas";
line_ptrs[3] = "rick";
line_ptrs[4] = "jones";
line_ptrs[5] = "washington";
line_ptrs[6] = "sarah";
line_ptrs[7] = "doyle";
line_ptrs[8] = "texas";
line_ptrs[9] = "sally";
line_ptrs[10] = "ericson";
line_ptrs[11] = "washington";
.....etc.
___________________________________

Now for the code:
//////////////////////////// SNIPPET OF CODE ///////////////////

PHP Code:

char state[20];

int q=0;

int y;

printf("Search for all people in a certain State...\"1\" exits...");

fgets(state,19,stdin);

while( (strcmp(state,"\n")) && (q=atoi(state) != 1))
  { 
/// the above means "while user hasn't entered a "1" or a newline..." 

   for(y=0;y<max_num;y++)  ///"max_num" defined elsewhere
           {
               if( strstr(line_ptrs[y],state) )
                {
                  printf("%s\n",line_ptrs[y-2]); //print first name
                  printf("%s\n",line_ptrs[y-1]);  //print last name
                }
            }

printf("Search for all people in a certain State...\"1\" exits...");

fgets(state,19,stdin);
  } 


///////////////////////// END SNIPPET///////////////////////////////

So even if ten of the pointers are "texas" only three successful "strstr()" attempts might work!

Or if there are eight "washington"s, strstr() might find seven!!

AAAAAAAARGH!

This inconsistancy shows thoughout the execution of this routine.

Any ideas?

You need a:
state[strlen(state)-1] = '\0';
just inside the while loop to remove the newline character.

Hmm, I'll try it but where exactly in the code?

Besides, it looks like you are simply replacing the char before the newline with a newline, instead of removing the newline from the string...

Anyway, are there any replacements for "strstr()"?

ugh
I hate when people think C is @ fault when they have bad code... and also strstr is not a part of C... it is jsut a part of the string lib. and also ststr is for a string... noto an array of poitners to strings... think, its not telepathic, how does it know that these are pointers to strings, where does it say "if this function is givin a string of strings, it will add them all together and scan that". No, it will just look for patterns in the pointers, not wut they are pointing to.

No Offence, SPH

Actually, the results were precisely the same whether I used the array of pointers or the array of arrays of chars(the actual table of strings). And since it did work some of the time, I figured there was just some subtlety I wasn't getting. BTW, I am not strstr()ing the whole damn thing at once! NOTICE the for() loop. One at a time. O.K.?

Personally, I think an strcmp() would be more efficient anyway
saves headaches sometimes, you should try it.... he's right, you're matching -exact- strings, why do something that you don't needa do Besides, it wouldn't be too hard to change

And, state[strlen(state)-1] = '\0'; is old... heheh use..
state[strlen(state)-1] = NULL; even though it's likely noone
cares :O

Sue me, I'm picky :P

Thanks Zoo! It works like a charm!

And as far as "strcmp()" is concerned guys, I will be adding data to each string, so "strstr()" type functions is what I'm looking for.

I simplified the problem to be more readable, and I confused a lot of people in the process!

But all is well now, thanks to all of your help. I can now go to sleep! Goodnight...