From 844c3e5e97a79da38c0a4b69610ad425774d7c30 Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Mon, 31 Jan 2022 08:42:07 -0800
Subject: [PATCH 32/43] hostname: simplify

* src/hostname.c (sethostname): Provide a substitute on all
platforms, to simplify the mainline code.
(main): Simplify.  Remove an IF_LINT.
Use main_exit rather than return.
---
 src/hostname.c | 41 +++++++++++++++++++----------------------
 1 file changed, 19 insertions(+), 22 deletions(-)

diff --git a/src/hostname.c b/src/hostname.c
index 69e38bb37..e07e98b2b 100644
--- a/src/hostname.c
+++ b/src/hostname.c
@@ -32,18 +32,22 @@
 
 #define AUTHORS proper_name ("Jim Meyering")
 
-#if !defined HAVE_SETHOSTNAME && defined HAVE_SYSINFO && \
-     defined HAVE_SYS_SYSTEMINFO_H
-# include <sys/systeminfo.h>
+#ifndef HAVE_SETHOSTNAME
+# if defined HAVE_SYSINFO && defined HAVE_SYS_SYSTEMINFO_H
+#  include <sys/systeminfo.h>
+# endif
 
 static int
-sethostname (char *name, size_t namelen)
+sethostname (char const *name, size_t namelen)
 {
+# if defined HAVE_SYSINFO && defined HAVE_SYS_SYSTEMINFO_H
   /* Using sysinfo() is the SVR4 mechanism to set a hostname. */
   return (sysinfo (SI_SET_HOSTNAME, name, namelen) < 0 ? -1 : 0);
+# else
+  errno = ENOTSUP;
+  return -1;
+# endif
 }
-
-# define HAVE_SETHOSTNAME 1  /* Now we have it... */
 #endif
 
 void
@@ -84,34 +88,27 @@ main (int argc, char **argv)
                                    Version, true, usage, AUTHORS,
                                    (char const *) NULL);
 
-  if (argc == optind + 1)
+  if (optind + 1 < argc)
+     {
+       error (0, 0, _("extra operand %s"), quote (argv[optind + 1]));
+       usage (EXIT_FAILURE);
+     }
+
+  if (optind + 1 == argc)
     {
-#ifdef HAVE_SETHOSTNAME
       /* Set hostname to operand.  */
       char const *name = argv[optind];
       if (sethostname (name, strlen (name)) != 0)
         die (EXIT_FAILURE, errno, _("cannot set name to %s"),
              quote (name));
-#else
-      die (EXIT_FAILURE, 0,
-           _("cannot set hostname; this system lacks the functionality"));
-#endif
     }
-
-  if (argc <= optind)
+  else
     {
       hostname = xgethostname ();
       if (hostname == NULL)
         die (EXIT_FAILURE, errno, _("cannot determine hostname"));
       puts (hostname);
-      IF_LINT (free (hostname));
-    }
-
-  if (optind + 1 < argc)
-    {
-      error (0, 0, _("extra operand %s"), quote (argv[optind + 1]));
-      usage (EXIT_FAILURE);
     }
 
-  return EXIT_SUCCESS;
+  main_exit (EXIT_SUCCESS);
 }
-- 
2.32.0