Add xgethostname.h.

[gnulib.git] / lib / xgethostname.c

diff --git a/lib/xgethostname.c b/lib/xgethostname.c
index 1139a1b..1f4d728 100644 (file)
--- a/lib/xgethostname.c
+++ b/lib/xgethostname.c
@@ -1,5 +1,5 @@
 /* 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
@@ -21,6 +21,10 @@
 # include <config.h>
 #endif
 
+/* Specification.  */
+#include "xgethostname.h"
+
+#include <stdlib.h>
 #include <sys/types.h>
 
 #include <errno.h>
@@ -29,46 +33,52 @@ extern int errno;
 #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;