Re: getline() bug

[John V. Shahid]

Thanks a lot for pointing that out.

I just wanted to point out to the fact that the MACRO that need to be
defined (GNU_SOURCE) isn't mentioned in the info pages of libc. Or at
least in the getline and getdelim section. I've been using getline for a
while and always had the warning about the implicit declaration but
thought it's kind of bug since I always include the mentioned header
files. Do you think I should send this to the current maintainers of the
info pages of libc ?

On Wed, 2007-07-25 at 13:36 -0700, Paul Pluzhnikov wrote:
> "John V. Shahid" <jvshahid@gmail.com> writes:
> 
> > I think I found a bug in getline().
> 
> Nope. The bug is in your program (but I'll grant you -- it's an
> obscure one).
> 
> Compile your code with -Wall, and you'll see this:
> 
> $ gcc -Wall junk3.c
> junk3.c: In function 'main':
> junk3.c:19: warning: implicit declaration of function 'getline'
> junk3.c:7: warning: unused variable 'count'
> 
> The 'man getline' tells you to do this:
>        #define _GNU_SOURCE
> 
> Adding that to junk3.c, and compiling again with -Wall, tells you
> the root of the problem:
> 
> junk3.c: In function 'main':
> junk3.c:20: warning: passing argument 2 of 'getline' from incompatible 
> pointer type
> 
> Fixing that problem:
> 
>       // int lineSize, count; 
>       size_t lineSize;
> 
> cures the warning, cures your bug, and makes valgrind happy:
> 
> ==28863== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 4 from 1)
> 
> Cheers,