Thread: glibc: corrupted double-linked list

Hi!! After some times lurking this is my first question...
I'm working on a function that should remove any tag from an HTML page and split all the remaining text into an array.
Here is the code:

Code:

char **html::getPageKeywords()
{
       Pattern * p = Pattern::compile("<body[^>]*?>(.+?)</body[^>]*?>");
   
       Matcher * m = p->createMatcher(getPage());

        char * c = getPage();//&v[0];

	std::string temp;
	temp=p->replace("<script[^>]*?>(.+?)</script[^>]*?>",c,"");
	temp=p->replace("<[^>]*?>",temp,"");
	temp=p->replace("</[^>]*?>",temp,"");
	temp=p->replace("<[^>]*?/>",temp,"");

	std::vector<char> z(temp.length() + 1);
	std::strcpy(&z[0], temp.c_str());
	c = &z[0];

	char *out = new char[(signed)strlen(c)+1]; 
        UnToken(c,tokens,out);  // removes characters like @ # $ % ^ & * ; : ' . and so on...
 
       char *no2spaces = new char[(signed)strlen(out)+1];
	no2spaces=out;
	OnlyOneSpace(no2spaces);  // removes doubled spaces
	
	char *pch = new char[(signed)strlen(out)];
	pch=strtok(no2spaces," ");

	char **keywords=new char*[(signed)strlen(out)];

	int x=0;
	while (pch!=NULL)
	{
		char * chiave=new char[strlen(pch)+1];
		chiave=pch;		

		if (chiave[0] != ' ' && strlen(chiave) != 0)
			keywords[x]=chiave;
		pch=strtok(NULL, " ");
		x++;
	}

    return keywords;    
}

It compiles and work for a little, then after some pages I get this error:

Code:

*** glibc detected *** corrupted double-linked list: 0x08b9b160 ***

Where 0x08b9b160 alwys change.

I can't figure out why...any idea?

Thank you in advance!

maybe some of the functions that you call, use double linked lists and they get corrupted somehow

Originally Posted by Salem

> char *no2spaces = new char[(signed)strlen(out)+1];
> no2spaces=out;
Maybe, you should stick to std::string rather than messing with char arrays.

This does NOT copy the string, it merely trashes your pointer to memory you allocated with a pointer to memory you didn't. The result is BOOM when it comes to freeing that memory.

You should have used
strcpy( no2spaces, out );

And why did you cast the result of strlen() ?

I understand! Thank you very much! I'm not an experienced programmer as you can see...
I also removed the cast of the strlen result...