1 files changed, 90 insertions, 0 deletions
diff --git a/src/whoami.c b/src/whoami.c
new file mode 100644
index 0000000..69c9ccc
--- /dev/null
+++ b/src/whoami.c
@@ -0,0 +1,90 @@
+/* whoami -- print effective userid
+
+   Copyright (C) 1989-2020 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/>.  */
+
+/* Equivalent to 'id -un'. */
+/* Written by Richard Mlynarik. */
+
+#include <config.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <pwd.h>
+
+#include "system.h"
+#include "die.h"
+#include "error.h"
+#include "long-options.h"
+#include "quote.h"
+
+/* The official name of this program (e.g., no 'g' prefix).  */
+#define PROGRAM_NAME "whoami"
+
+#define AUTHORS proper_name ("Richard Mlynarik")
+
+void
+usage (int status)
+{
+  if (status != EXIT_SUCCESS)
+    emit_try_help ();
+  else
+    {
+      printf (_("Usage: %s [OPTION]...\n"), program_name);
+      fputs (_("\
+Print the user name associated with the current effective user ID.\n\
+Same as id -un.\n\
+\n\
+"), stdout);
+      fputs (HELP_OPTION_DESCRIPTION, stdout);
+      fputs (VERSION_OPTION_DESCRIPTION, stdout);
+      emit_ancillary_info (PROGRAM_NAME);
+    }
+  exit (status);
+}
+
+int
+main (int argc, char **argv)
+{
+  struct passwd *pw;
+  uid_t uid;
+  uid_t NO_UID = -1;
+
+  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);
+    }
+
+  errno = 0;
+  uid = geteuid ();
+  pw = (uid == NO_UID && errno ? NULL : getpwuid (uid));
+  if (!pw)
+    die (EXIT_FAILURE, errno, _("cannot find name for user ID %lu"),
+         (unsigned long int) uid);
+  puts (pw->pw_name);
+  return EXIT_SUCCESS;
+}