1 files changed, 112 insertions, 0 deletions
diff --git a/src/hostname.c b/src/hostname.c
new file mode 100644
index 0000000..115cac2
--- /dev/null
+++ b/src/hostname.c
@@ -0,0 +1,112 @@
+/* hostname - set or print the name of current host system
+   Copyright (C) 1994-2023 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 3 of the License, 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, see <https://www.gnu.org/licenses/>.  */
+
+/* Written by Jim Meyering.  */
+
+#include <config.h>
+#include <stdio.h>
+#include <sys/types.h>
+
+#include "system.h"
+#include "long-options.h"
+#include "quote.h"
+#include "xgethostname.h"
+
+/* The official name of this program (e.g., no 'g' prefix).  */
+#define PROGRAM_NAME "hostname"
+
+#define AUTHORS proper_name ("Jim Meyering")
+
+#ifndef HAVE_SETHOSTNAME
+# if defined HAVE_SYSINFO && defined HAVE_SYS_SYSTEMINFO_H
+#  include <sys/systeminfo.h>
+# endif
+
+static int
+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
+}
+#endif
+
+void
+usage (int status)
+{
+  if (status != EXIT_SUCCESS)
+    emit_try_help ();
+  else
+    {
+      printf (_("\
+Usage: %s [NAME]\n\
+  or:  %s OPTION\n\
+Print or set the hostname of the current system.\n\
+\n\
+"),
+             program_name, program_name);
+      fputs (HELP_OPTION_DESCRIPTION, stdout);
+      fputs (VERSION_OPTION_DESCRIPTION, stdout);
+      emit_ancillary_info (PROGRAM_NAME);
+    }
+  exit (status);
+}
+
+int
+main (int argc, char **argv)
+{
+  char *hostname;
+
+  initialize_main (&argc, &argv);
+  set_program_name (argv[0]);
+  setlocale (LC_ALL, "");
+  bindtextdomain (PACKAGE, LOCALEDIR);
+  textdomain (PACKAGE);
+
+  atexit (close_stdout);
+
+  parse_gnu_standard_options_only (argc, argv, PROGRAM_NAME, PACKAGE_NAME,
+                                   Version, true, usage, AUTHORS,
+                                   (char const *) nullptr);
+
+  if (optind + 1 < argc)
+     {
+       error (0, 0, _("extra operand %s"), quote (argv[optind + 1]));
+       usage (EXIT_FAILURE);
+     }
+
+  if (optind + 1 == argc)
+    {
+      /* Set hostname to operand.  */
+      char const *name = argv[optind];
+      if (sethostname (name, strlen (name)) != 0)
+        error (EXIT_FAILURE, errno, _("cannot set name to %s"),
+               quote (name));
+    }
+  else
+    {
+      hostname = xgethostname ();
+      if (hostname == nullptr)
+        error (EXIT_FAILURE, errno, _("cannot determine hostname"));
+      puts (hostname);
+    }
+
+  main_exit (EXIT_SUCCESS);
+}