Segmentation fault <Address 0xa0 out of bounds>

**J4e8a16n** · 02/08/2018, 21h21

Bonjour à tous,

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/* p 144 - 147  K&R */
 
 
/*   C:\JPD\AStyle.exe   --style=vtk --indent=spaces=2 --pad-oper --pad-comma  --align-pointer=name  --add-brackets  --indent-switches  --delete-empty-lines  */
/*   hash : form hash value from string s */
 
 
 
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
 
#define HASHSIZE 201
static struct nlist *hashtab[HASHSIZE] ;     /*   pointer table */
struct nlist *lookup (char *s);
struct nlist *install (char *name, char *defn);
unsigned hash (char *s);
char *strduup(char *s);
 
int i = 0;
unsigned char stat[100];
 
struct nlist
{
struct nlist *next;	/*   next entry in chain */
char *name;			/*   defined name */
char *defn;			/*   replacement text */
};
 
 
/*   make a duplicate of s */
char *strduup(char *s)
{
char *p;
 
p = (char *) malloc ((strlen(s)+1));  /*  + 1  for '\0' */
if (p != NULL)
	strcpy(p, s);
return p;
}
 
/*   install:  put (name defn) in hashtab */
 
struct nlist *install (char *name, char *defn)
{
struct nlist *np;
unsigned hashval;
 
	if ((np = lookup(name)) == NULL)
	{
	np = (struct nlist *) malloc(sizeof(*np));	/*   not found */
		if (np == NULL || (np->name = strduup(name)) == NULL)
			return NULL;
	hashval = hash(name);
	np->next = hashtab[hashval];
	hashtab[hashval] = np;
	}else					/*   already there */
	free ((void *) np->defn);	/*   free previous defn */
	if ((np->defn = strduup(defn)) == NULL)
			return NULL;
 
printf("defn= %p  name = %p", np->defn, np->name);
	return np;
}
 
 
/*   lookup  ; look for s in hashtab */
 
struct nlist *lookup (char *s)
{
struct nlist *np;
 
for (np =hashtab[hash(s)]; np != NULL ; np = np->next)
	if (strcmp(s, np->name ) == 0)
		return np;        /*   found */
 
	return NULL;		/*    not found */
}
 
 
 
 
int main(void)
{
char unhello [] = "Hello, world.";
int j;
 
	install (unhello, (char *)hash ("Hello, world."));
	hash ("hello, world.");
	hash ("Helo, world.");
	hash ("Hella, world.");
	hash ("Hello, World.");
	hash ("Hello, WOrld.");
	hash ("Hello, worldd.");
	hash ("Hello, wfrld.");
	hash ("Hello, worf.");
	hash ("Hlo, world.");
	hash ("Hello, world.");
 
 
	printf("\n\nstat = ");
	for (j =0;j<i ;j++ )
	{
	printf("\t%d", stat[j]);
	}
 
	return 0;
}
 
 
unsigned hash (char *s)
{
 unsigned hashval;
 
 /*   printf("\nhashval = %u\n", hashval); */
  for (hashval = 0; *s != '\0' ; s++ )
    {
    hashval += *s + (31 * hashval);
	printf("\n*s=%u + 31 * hashval = %u\t\t\t s = %s\n", *s, hashval, s );
    }
	stat[i] = (hashval % HASHSIZE);
	i++;
	printf("\n\n\t\ti = %d\t\t\tmodulo = %d\n", i, stat[i-1]);
 
  return hashval % HASHSIZE;
}
 
int undef(char * name) {
    struct nlist * np1, * np2;
 
    if ((np1 = lookup(name)) == NULL)  /*  name not found  */
        return 1;
 
    for ( np1 = np2 = hashtab[hash(name)]; np1 != NULL;
          np2 = np1, np1 = np1->next ) {
        if ( strcmp(name, np1->name) == 0 ) {  /*  name found  */
 
            /*  Remove node from list  */
 
            if ( np1 == np2 )
                hashtab[hash(name)] = np1->next;
            else
                np2->next = np1->next;
 
            /*  Free memory  */
 
            free(np1->name);
            free(np1->defn);
            free(np1);
 
            return 0;
        }
    }
 
    return 1;  /*  name not found  */
}

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Debugger name and version: GNU gdb (GDB) 7.5
Child process PID: 9028
Program received signal SIGSEGV, Segmentation fault.
In strlen () (C:\WINDOWS\SysWOW64\msvcrt.dll)
#1  0x00401345 in strduup (s=0xa0 <Address 0xa0 out of bounds>) at C:\Users\Another\codbloc\cb_htbl\p147.c:37
C:\Users\Another\codbloc\cb_htbl\p147.c:37:793:beg:0x401345
At C:\Users\Another\codbloc\cb_htbl\p147.c:37
#1  0x00401345 in strduup (s=0xa0 <Address 0xa0 out of bounds>) at C:\Users\Another\codbloc\cb_htbl\p147.c:37
C:\Users\Another\codbloc\cb_htbl\p147.c:37:793:beg:0x401345