+/* xgethostname.c -- return current hostname with unlimited length
+ Copyright (C) 1992, 1996, 2000, 2001 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
+ the Free Software Foundation; either version 2, or (at your option)
+ any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software Foundation,
+ Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+
+/* written by Jim Meyering */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
#include <sys/types.h>
+#include <errno.h>
+#ifndef errno
+extern int errno;
+#endif
+
+#include "error.h"
+#include "xalloc.h"
+
+#ifndef ENAMETOOLONG
+# define ENAMETOOLONG 9999
+#endif
+
+#ifndef EXIT_FAILURE
+# define EXIT_FAILURE 1
+#endif
+
int gethostname ();
-char *xmalloc ();
-char *xrealloc ();
-#define INITIAL_HOSTNAME_LENGTH 33
+#ifndef INITIAL_HOSTNAME_LENGTH
+# define INITIAL_HOSTNAME_LENGTH 34
+#endif
char *
xgethostname ()
{
char *hostname;
size_t size;
- int err;
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);
while (1)
{
- hostname = xmalloc (size);
- hostname[size - 1] = '\0';
+ int k = size - 1;
+ int err;
+
+ errno = 0;
+ hostname[k] = '\0';
err = gethostname (hostname, size);
- if (err || hostname[size - 1] == '\0')
+ 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);
+ hostname = xrealloc (hostname, size + 1);
}
return hostname;