Re: The patch of glibc which allows the user to override the pfinet server

[zhengda]

olafBuddenhagen@gmx.net wrote:
> Hi,
>
> On Tue, Aug 12, 2008 at 08:05:49PM +0200, zhengda wrote:
>
>   
> > +      char *name = NULL;
> >     
>
> No need to initialize this -- the asprintf() will overwrite it anyways.
>   
But isn't it always right to initialize a local variable to reduce the 
possibility of getting bugs?
>   
> > +      if (__asprintf (&name, "SOCK_SERV_%d", domain) > 0)
> > +        {
> > +          np = getenv (name);
> > +          __free (name);
> > +        }
> >     
>
> You need to check whether asprintf() returns an error code (-1), meaning
> memory allocation failed, and handle it accordingly -- just like you
> handled failure with the explicit malloc() in your original code.
>   
as I understand from the manual of asprintf, asprintf always returns -1 
if there is some error.

RETURN VALUE
      When  successful,  these  functions return the number of bytes 
printed,
      just like sprintf(3).  If memory allocation wasn't  possible,  
or  some
      other error occurs, these functions will return -1, and the 
contents of
      strp is undefined.

> If asprintf() doesn't fail, the getenv() should be done unconditionally.
>
>   
> > +          if (__asprintf (&name, "%s/%d", sock_servs, domain) > 0)
> > +              np = name;
> >     
>
> I think you can print to np directly here...
I need to free the space afterwards.
If I use np directly, I'll not be able to figure out whether I should 
free the memory because np might point to the environment variable.

Zheng Da