Can someone tell me why the code below should segfault at the line 
indicated?

Also, why does strtok_r() require a **ptrptr and not a *ptr?
(Maybe this is a clue to my problem and misunderstanding of how strtok_r 
is used...).

Thanks for any insight.

-Randy

PS: str arg is always guaranteed to point to a valid string < 127 chars


void getNameValuePairFromString(char * str, string & name, string & value)
{
    char * buf = (char *) malloc(128);
    char * tok = strtok_r(str, " =\n\r", &buf);
    if (tok != NULL)
    {
       name = tok;
       tok = strtok_r(NULL, " =\n\r", &buf);
       if (tok != NULL)
          value = tok;
    }
    free(buf); // seg fault here !!!
}

On Fri, 17 Sep 2004 16:06:25 -0700, RJGraham wrote:

> Can someone tell me why the code below should segfault at the line 
> indicated?
> 
> Also, why does strtok_r() require a **ptrptr and not a *ptr?
Because how else could it change the pointer you supplied ?

> (Maybe this is a clue to my problem and misunderstanding of how strtok_r 
> is used...).
> 
> Thanks for any insight.
> 
> -Randy
> 
> PS: str arg is always guaranteed to point to a valid string < 127 chars
> 
> 
> void getNameValuePairFromString(char * str, string & name, string & value)
> {
You are changing the buf pointer with the calls to
strtok_r, so when you free it, buf doesn't point to
what you malloced.
Do;

     char * buffer = (char *) malloc(128);
     char *buf = buffer;
>     char * tok = strtok_r(str, " =\n\r", &buf);
>     if (tok != NULL)
>     {
>        name = tok;
>        tok = strtok_r(NULL, " =\n\r", &buf);
>        if (tok != NULL)
>           value = tok;
>     }

>     free(buf); // seg fault here !!!
And;
      free(buffer);
> }
You can probably avoid the malloc/free stuff alltogether, perhaps
just initializing buf to NULL suffices. Never used strtok, and my docs
doesn't do a very good job explaining the _r version though..