1 files changed, 86 insertions, 0 deletions
diff --git a/src/hostid.c b/src/hostid.c
new file mode 100644
index 0000000..0cd3dd5
--- /dev/null
+++ b/src/hostid.c
@@ -0,0 +1,86 @@
+/* print the hexadecimal identifier for the current host
+
+   Copyright (C) 1997-2020 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 "error.h"
+#include "quote.h"
+
+/* The official name of this program (e.g., no 'g' prefix).  */
+#define PROGRAM_NAME "hostid"
+
+#define AUTHORS proper_name ("Jim Meyering")
+
+void
+usage (int status)
+{
+  if (status != EXIT_SUCCESS)
+    emit_try_help ();
+  else
+    {
+      printf (_("\
+Usage: %s [OPTION]\n\
+Print the numeric identifier (in hexadecimal) for the current host.\n\
+\n\
+"), 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)
+{
+  unsigned int id;
+
+  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 *) NULL);
+
+  if (optind < argc)
+    {
+      error (0, 0, _("extra operand %s"), quote (argv[optind]));
+      usage (EXIT_FAILURE);
+    }
+
+  id = gethostid ();
+
+  /* POSIX says gethostid returns a "32-bit identifier" but is silent
+     whether it's sign-extended.  Turn off any sign-extension.  This
+     is a no-op unless unsigned int is wider than 32 bits.  */
+  id &= 0xffffffff;
+
+  printf ("%08x\n", id);
+
+  return EXIT_SUCCESS;
+}