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/* Test case for gethostbyname_r bug when buffer expansion required. */
#include <netdb.h>
#include <arpa/inet.h>
#include <errno.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
int
main (void)
{
const char *host = "www.gnu.org";
/* This code approximates the example code in the library manual. */
struct hostent hostbuf, *hp;
size_t hstbuflen;
char *tmphstbuf;
int res;
int herr;
hstbuflen = 16; /* Make it way small to ensure ERANGE. */
/* Allocate buffer, remember to free it to avoid memory leakage. */
tmphstbuf = malloc (hstbuflen);
while ((res = gethostbyname_r (host, &hostbuf, tmphstbuf, hstbuflen,
&hp, &herr)) == ERANGE)
{
/* Enlarge the buffer. */
hstbuflen *= 2;
tmphstbuf = realloc (tmphstbuf, hstbuflen);
}
if (res != 0 || hp == NULL)
{
printf ("gethostbyname_r failed: %s (errno: %m)\n", strerror (res));
if (access ("/etc/resolv.conf", R_OK))
{
puts ("DNS probably not set up");
return 0;
}
return 1;
}
printf ("Got: %s %s\n", hp->h_name,
inet_ntoa (*(struct in_addr *) hp->h_addr));
return 0;
}
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