在结构内部使用C Struct会导致分段错误错误

Question

Here is the structure of the data:

    struct variabile {
        char* nome;         
        char* contenuto;        
        struct variabile* next;     
        int tipo;           
    };

And here is the code:

    struct variabile* pt = malloc (sizeof (struct variabile));
            pt->nome = $1; 
            pt->tipo = type; 
            pt->contenuto = $2; 
            pt->next=NULL;      


    if (testaVariabile == NULL) 
            testaVariabile=pt; 
    else {
            struct variabile* current = testaVariabile;


        while ((current->next)!=NULL){  

            if(strcmp(current->nome, pt->nome)==0)
                                    fprintf (stderr, "warning: clash di nome di variabili %s \n", current->nome);
            current=(current->next); 
        }
        (current->next)=pt; 

        if(strcmp(current->nome, pt->nome)==0) 
                fprintf (stderr, "warning: clash di nome di variabili %s \n", current->nome);
    }

Here is the initial declaration of the variable testaVariabile .

       struct variabile* testaVariabile = NULL;

I get a segmentation fault error when I try to update the next value of current in the last line of code. I have also verified that the code didn't enter the while cycle.

I'm pretty new to C, so please explain the answer.

Thank you

EDIT

The rest of the code is a Flex parser.

EDIT

A friend of mine tell me to debug using gdb. It comes out that the error cames out from

       strcmp(current->nome, pt->nome)

I'm really sorry for the time lost looking for the problem in the wrong place, but this is my first serious time with C and Flex.

Somebody knows how to get rid of this problem?

Ok, last update.

The checked answer solved the problem. But in this case there was also an error in the way that the lexer read the value from the file, so it was a two-part problem.

Answer 1

Try this:

struct variabile* pt = malloc (sizeof (struct variabile));
pt->nome = malloc(strlen($1) + 1);
strcpy(pt->nome, $1); 
pt->tipo = type; 
pt->contenuto = $2; // maybe the same for this too?
pt->next=NULL;

/* rest of your code ... */

just a wild guess though