structures

[elb0m]

ok,i'm trying to build a program, with socket connections. but i'm having difficulties in structures.
i can't figure out the problem of this code.
it brings me Segmation Fault after gcc compiling.
i hope you will help me with this.

#include <stdio.h>
#include <string.h>

struct topics {
 int topicID;
 char *baseTopicName;
 struct messages* thema;
} staticTopics[6];

struct messages {
  char *topicName;
  char *sender;
  char *message;

};

int main(){
     staticTopics[1].thema[1].topicName="aasss";


   
}

[tabstop]

And why do you think thema[1] even exists? Thema is a pointer, and you didn't initialize it, or provide any memory for it to point to, so far as I can see here, so it's not pointing to anything in particular. Trying to follow that pointer leads to Bad Things.

[jason_m]

thema is just a pointer - a piece of memory large enough to hold another memory address, there is not actually any space allocated for any struct messages data types, yet. You need to do this. Say you want N of these. Then you can do,

staticTopics[i].thema = malloc(N * sizeof(struct messages));

Also note that in C array indexes start at zero. So the elements of staticTopics are [0]-[5].

Good luck

[elb0m]

thanks jason_m.