segmentation fault while running the programme - c

Question

I have written code for parsing a string into words. Here is code. Can any one help here to fix the segmentation fault error during run time?
Calling fun :
int main()
{
int count = 0, i; // count to hold numbr of words in the string line.
char buf[MAX_LENTHS]; // buffer to hold the string
char *options[MAX_ORGS]; // options to hold the words that we got after parsing.
printf("enter string");
scanf("%s",buf);
count = parser(buf,options); // calling parser
for(i = 0; i < count; ++i)
printf("option %d is %s", i, options[i]);
return 0;
}
Called function:
int parser(char str[], char *orgs[])
{
char temp[1000];//(char *)malloc(strlen(str)*sizeof(char));
int list = 0;
strcpy(temp, str);
*orgs[list]=strtok(str, " \t ");
while(((*orgs[list++]=strtok(str," \t"))!=NULL)&&MAX_ORGS>list)
list++;
printf("count =%d",list);
return list;
}
Note : I'm trying to learn C these days, can any one help to get a good tutorial (pdf) or site to learn these strings with pointers, and sending string to functions as arguments?

Answer 1

You are using strtok wrong.
(It is generally best to not use strtok at all, for all its problems and pitfalls.)
If you must use it, the proper way to use strtok is to call it ONCE with the string you want to "tokenize",
then call it again and again with NULL as an indication to continue parsing the original string.
I also think you're using the orgs array wrong.
Change this assignment
*orgs[list++]=strtok(str, " \t ");
to this:
orgs[list++]=strtok(str, " \t ");
Because orgs is an array of character-pointers.
orgs[x] is a character-pointer, which matches the return-type of strtok
Instead, you are referring to *orgs[x], which is just a character.
So you are trying to do:
[character] = [character-pointer];
which will result in "very-bad-things™".
Finally, note that you are incrementing list twice each time through your loop.
So basically you're only filling in the even-elements, leaving the odd-elements of orgs uninitialized.
Only increment list once per loop.
Basically, you want this:
orgs[list++] = strtok(str, " \t ");
while(( (orgs[list++] = strtok(NULL," \t")) !=NULL) && MAX_ORGS > list)
/* do nothing */;
PS You allocate space for temp, and strcpy into it.
But then it looks like you never use it. Explain what temp is for, or remove it.

Answer 2

char buf[MAX_LENTHS];
You have not defined the array size, i. e. MAX_LENTHS should be defined like
#define MAX_LENTHS 25
And as Paul R says in his comment you also need to initialize your array of character pointers
char *options[MAX_ORGS];
with something .

Answer 3

int parser(char str[], char *orgs[]){
int list=0;
orgs[list]=strtok(str, " \t\n");
while(orgs[list]!=NULL && ++list < MAX_ORGS)
orgs[list]=strtok(NULL," \t\n");
printf("count = %d\n",list);
return list;
}
int main(){
int count=0,i;
char buf[MAX_LENTHS];
char *options[MAX_ORGS];
printf("enter string: ");
fgets(buf, sizeof(buf), stdin);//input include space character
count=parser(buf,options);
for(i=0;i<count;++i)
printf("option %d is %s\n",i,options[i]);
return 0;
}