/* xgethostname.c -- return current hostname with unlimited length
- Copyright (C) 1992, 1996 Free Software Foundation, Inc.
+ Copyright (C) 1992, 1996, 2000, 2001, 2003 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
# include <config.h>
#endif
+/* Specification. */
+#include "xgethostname.h"
+
+#include <stdlib.h>
#include <sys/types.h>
#include <errno.h>
#endif
#include "error.h"
+#include "exit.h"
+#include "xalloc.h"
-#ifndef EXIT_FAILURE
-# define EXIT_FAILURE 1
+#ifndef ENAMETOOLONG
+# define ENAMETOOLONG 9999
#endif
int gethostname ();
-char *xmalloc ();
-char *xrealloc ();
#ifndef INITIAL_HOSTNAME_LENGTH
# define INITIAL_HOSTNAME_LENGTH 34
#endif
+/* Return the current hostname in malloc'd storage.
+ If malloc fails, exit.
+ Upon any other failure, return NULL. */
char *
-xgethostname ()
+xgethostname (void)
{
char *hostname;
size_t size;
- int err;
size = INITIAL_HOSTNAME_LENGTH;
- hostname = xmalloc (size);
+ /* Use size + 1 here rather than size to work around the bug
+ in SunOS 5.5's gethostname whereby it NUL-terminates HOSTNAME
+ even when the name is longer than the supplied buffer. */
+ hostname = xmalloc (size + 1);
while (1)
{
- /* Use size - 2 here rather than size - 1 to work around the bug
- in SunOS5.5's gethostname whereby it NUL-terminates HOSTNAME
- even when the name is longer than the supplied buffer. */
- int k = size - 2;
+ int k = size - 1;
+ int err;
errno = 0;
hostname[k] = '\0';
err = gethostname (hostname, size);
- if (err == 0 && hostname[k] == '\0')
+ if (err >= 0 && hostname[k] == '\0')
break;
-#ifdef ENAMETOOLONG
- else if (err != 0 && errno != ENAMETOOLONG && errno != 0)
- error (EXIT_FAILURE, errno, "gethostname");
-#endif
+ else if (err < 0 && errno != ENAMETOOLONG && errno != 0)
+ {
+ int saved_errno = errno;
+ free (hostname);
+ errno = saved_errno;
+ return NULL;
+ }
size *= 2;
- hostname = xrealloc (hostname, size);
+ hostname = xrealloc (hostname, size + 1);
}
return hostname;