GCC finding errors in MinGW's stdio.h - c

Question

I'm trying to compile some example C code with GCC/MinGW on Windows 7. The example code includes some local header files which ultimately include stdio.h, and I get this error when I try to compile:
c:\mingw\include\stdio.h:345:12: error: expected '=', ',', ';', 'asm' or '__attribute__' before '__mingw__snprintf'
extern int __mingw_stdio_redirect__(snprintf)(char*, size_t, const char*, ...);
This is a weird one to me. How could there possibly be errors in stdio.h?

Answer 1

regarding:
if (i == 0)
{
printf("\nNo interfaces found! Make sure WinPcap is installed.\n");
return 0;
}
pcap_freealldevs(alldevs);
since the variable i is initialized to 0 and never modified, this if() statement will always be true. One result is the call to: pcap_freealldev() will never be called.
the scope of variables should be limited as much as reasonable.
Code should never depend on the OS to clean up after itself. suggest
#include <stdio.h>
#include <stdlib.h>
#include "pcap.h"
int main( void )
{
pcap_if_t *alldevs = NULL;
char errbuf[PCAP_ERRBUF_SIZE];
/* Retrieve the device list from the local machine */
if (pcap_findalldevs_ex(PCAP_SRC_IF_STRING, NULL /* auth is not needed */, &alldevs, errbuf) == -1)
{
fprintf(stderr,"Error in pcap_findalldevs_ex: %s\n", errbuf);
exit(1);
}
/* Print the list */
for( pcap_if_t *d = alldevs; d != NULL; d= d->next)
{
printf("%d. %s", ++i, d->name);
if (d->description)
printf(" (%s)\n", d->description);
else
printf(" (No description available)\n");
}
if ( ! alldevs )
{
printf("\nNo interfaces found! Make sure WinPcap is installed.\n");
}
/* We don't need any more the device list. Free it */
pcap_freealldevs(alldevs);
}