/* xgethostname.c -- return current hostname with unlimited length
- Copyright (C) 1992, 1996, 2000, 2001 Free Software Foundation, Inc.
+
+ Copyright (C) 1992, 1996, 2000, 2001, 2003, 2004 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
-#include <sys/types.h>
+/* Specification. */
+#include "xgethostname.h"
+#include <stdlib.h>
#include <errno.h>
-#ifndef errno
-extern int errno;
+
+#if HAVE_UNISTD_H
+# include <unistd.h>
#endif
-#include "error.h"
#include "xalloc.h"
#ifndef ENAMETOOLONG
-# define ENAMETOOLONG 9999
-#endif
-
-#ifndef EXIT_FAILURE
-# define EXIT_FAILURE 1
+# define ENAMETOOLONG 0
#endif
-int gethostname ();
-
#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 and set errno. */
char *
-xgethostname ()
+xgethostname (void)
{
- char *hostname;
- size_t size;
-
- size = INITIAL_HOSTNAME_LENGTH;
- /* Use size + 1 here rather than size 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. */
- hostname = xmalloc (size + 1);
+ char *hostname = NULL;
+ size_t size = INITIAL_HOSTNAME_LENGTH;
+
while (1)
{
- int k = size - 1;
- int err;
-
+ /* 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 as long as the supplied buffer. */
+ size_t size_1;
+
+ hostname = x2realloc (hostname, &size);
+ size_1 = size - 1;
+ hostname[size_1 - 1] = '\0';
errno = 0;
- hostname[k] = '\0';
- err = gethostname (hostname, size);
- if (err >= 0 && hostname[k] == '\0')
- break;
- else if (err < 0 && errno != ENAMETOOLONG && errno != 0)
- error (EXIT_FAILURE, errno, "gethostname");
- size *= 2;
- hostname = xrealloc (hostname, size + 1);
+
+ if (gethostname (hostname, size_1) == 0)
+ {
+ if (! hostname[size_1 - 1])
+ break;
+ }
+ else if (errno != 0 && errno != ENAMETOOLONG && errno != EINVAL)
+ {
+ int saved_errno = errno;
+ free (hostname);
+ errno = saved_errno;
+ return NULL;
+ }
}
return hostname;