xreadlink.c (xreadlink): AIX and HP-UX readlink return -1

[gnulib.git] / lib / xgethostname.c

diff --git a/lib/xgethostname.c b/lib/xgethostname.c
index e24124c..7b29176 100644 (file)
--- a/lib/xgethostname.c
+++ b/lib/xgethostname.c
@@ -1,5 +1,7 @@
 /* xgethostname.c -- return current hostname with unlimited length
-   Copyright (C) 1992, 1996, 2000 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
@@ -21,56 +23,59 @@
 # 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 EXIT_FAILURE
-# define EXIT_FAILURE 1
+#ifndef ENAMETOOLONG
+# define ENAMETOOLONG 0
 #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 and set errno.  */
 char *
-xgethostname ()
+xgethostname (void)
 {
-  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);
+  char *hostname = NULL;
+  size_t size = INITIAL_HOSTNAME_LENGTH;
+
   while (1)
     {
-      int k = size - 1;
+      /* 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;
-#ifdef ENAMETOOLONG
-      else if (err < 0 && errno != ENAMETOOLONG && errno != 0)
-#else
-      else if (err < 0 && errno != 0)
-#endif
-       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;