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diff -uNr coreutils-8.30/build-aux/gen-lists-of-programs.sh coreutils-8.30+iPhone/build-aux/gen-lists-of-programs.sh
--- coreutils-8.30/build-aux/gen-lists-of-programs.sh	2017-04-30 19:00:58.000000000 -1000
+++ coreutils-8.30+iPhone/build-aux/gen-lists-of-programs.sh	2018-08-02 23:08:50.000000000 -1000
@@ -49,6 +49,7 @@
     cat
     chcon
     chgrp
+    su
     chmod
     chown
     cksum
diff -uNr coreutils-8.30/src/local.mk coreutils-8.30+iPhone/src/local.mk
--- coreutils-8.30/src/local.mk	2018-06-24 14:43:17.000000000 -1000
+++ coreutils-8.30+iPhone/src/local.mk	2018-08-02 23:08:01.000000000 -1000
@@ -101,6 +101,7 @@
 src_cat_LDADD = $(LDADD)
 src_chcon_LDADD = $(LDADD)
 src_chgrp_LDADD = $(LDADD)
+src_su_LDADD = $(LDADD)
 src_chmod_LDADD = $(LDADD)
 src_chown_LDADD = $(LDADD)
 src_chroot_LDADD = $(LDADD)
@@ -364,6 +365,7 @@
   src/relpath.c src/relpath.h
 src_chown_SOURCES = src/chown.c src/chown-core.c
 src_chgrp_SOURCES = src/chgrp.c src/chown-core.c
+src_su_SOURCES = src/su.c
 src_kill_SOURCES = src/kill.c src/operand2sig.c
 src_realpath_SOURCES = src/realpath.c src/relpath.c src/relpath.h
 src_timeout_SOURCES = src/timeout.c src/operand2sig.c
diff -uNr coreutils-8.30/src/su.c coreutils-8.30+iPhone/src/su.c
--- coreutils-8.30/src/su.c	1969-12-31 14:00:00.000000000 -1000
+++ coreutils-8.30+iPhone/src/su.c	2018-08-02 23:05:53.000000000 -1000
@@ -0,0 +1,522 @@
+/* su for GNU.  Run a shell with substitute user and group IDs.
+   Copyright (C) 1992-2006, 2008 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 <http://www.gnu.org/licenses/>.  */
+
+/* Run a shell with the real and effective UID and GID and groups
+   of USER, default `root'.
+
+   The shell run is taken from USER's password entry, /bin/sh if
+   none is specified there.  If the account has a password, su
+   prompts for a password unless run by a user with real UID 0.
+
+   Does not change the current directory.
+   Sets `HOME' and `SHELL' from the password entry for USER, and if
+   USER is not root, sets `USER' and `LOGNAME' to USER.
+   The subshell is not a login shell.
+
+   If one or more ARGs are given, they are passed as additional
+   arguments to the subshell.
+
+   Does not handle /bin/sh or other shells specially
+   (setting argv[0] to "-su", passing -c only to certain shells, etc.).
+   I don't see the point in doing that, and it's ugly.
+
+   This program intentionally does not support a "wheel group" that
+   restricts who can su to UID 0 accounts.  RMS considers that to
+   be fascist.
+
+   Compile-time options:
+   -DSYSLOG_SUCCESS	Log successful su's (by default, to root) with syslog.
+   -DSYSLOG_FAILURE	Log failed su's (by default, to root) with syslog.
+
+   -DSYSLOG_NON_ROOT	Log all su's, not just those to root (UID 0).
+   Never logs attempted su's to nonexistent accounts.
+
+   Written by David MacKenzie <djm@gnu.ai.mit.edu>.  */
+
+#include <config.h>
+#include <stdio.h>
+#include <getopt.h>
+#include <sys/types.h>
+#include <pwd.h>
+#include <grp.h>
+
+/* Hide any system prototype for getusershell.
+   This is necessary because some Cray systems have a conflicting
+   prototype (returning `int') in <unistd.h>.  */
+#define getusershell _getusershell_sys_proto_
+
+#include "system.h"
+#include "getpass.h"
+
+#undef getusershell
+
+#if HAVE_SYSLOG_H && HAVE_SYSLOG
+# include <syslog.h>
+#else
+# undef SYSLOG_SUCCESS
+# undef SYSLOG_FAILURE
+# undef SYSLOG_NON_ROOT
+#endif
+
+#if HAVE_SYS_PARAM_H
+# include <sys/param.h>
+#endif
+
+#ifndef HAVE_ENDGRENT
+# define endgrent() ((void) 0)
+#endif
+
+#ifndef HAVE_ENDPWENT
+# define endpwent() ((void) 0)
+#endif
+
+#if HAVE_SHADOW_H
+# include <shadow.h>
+#endif
+
+#include "error.h"
+
+/* The official name of this program (e.g., no `g' prefix).  */
+#define PROGRAM_NAME "su"
+
+#define AUTHORS proper_name ("David MacKenzie")
+
+#if HAVE_PATHS_H
+# include <paths.h>
+#endif
+
+/* The default PATH for simulated logins to non-superuser accounts.  */
+#ifdef _PATH_DEFPATH
+# define DEFAULT_LOGIN_PATH _PATH_DEFPATH
+#else
+# define DEFAULT_LOGIN_PATH ":/usr/ucb:/bin:/usr/bin"
+#endif
+
+/* The default PATH for simulated logins to superuser accounts.  */
+#ifdef _PATH_DEFPATH_ROOT
+# define DEFAULT_ROOT_LOGIN_PATH _PATH_DEFPATH_ROOT
+#else
+# define DEFAULT_ROOT_LOGIN_PATH "/usr/ucb:/bin:/usr/bin:/etc"
+#endif
+
+/* The shell to run if none is given in the user's passwd entry.  */
+#define DEFAULT_SHELL "/bin/sh"
+
+/* The user to become if none is specified.  */
+#define DEFAULT_USER "root"
+
+char *crypt (char const *key, char const *salt);
+char *getusershell (void);
+void endusershell (void);
+void setusershell (void);
+
+extern char **environ;
+
+static void run_shell (char const *, char const *, char **, size_t)
+     ATTRIBUTE_NORETURN;
+
+/* If true, pass the `-f' option to the subshell.  */
+static bool fast_startup;
+
+/* If true, simulate a login instead of just starting a shell.  */
+static bool simulate_login;
+
+/* If true, change some environment vars to indicate the user su'd to.  */
+static bool change_environment;
+
+static struct option const longopts[] =
+{
+  {"command", required_argument, NULL, 'c'},
+  {"fast", no_argument, NULL, 'f'},
+  {"login", no_argument, NULL, 'l'},
+  {"preserve-environment", no_argument, NULL, 'p'},
+  {"shell", required_argument, NULL, 's'},
+  {GETOPT_HELP_OPTION_DECL},
+  {GETOPT_VERSION_OPTION_DECL},
+  {NULL, 0, NULL, 0}
+};
+
+/* Add NAME=VAL to the environment, checking for out of memory errors.  */
+
+static void
+xsetenv (char const *name, char const *val)
+{
+  size_t namelen = strlen (name);
+  size_t vallen = strlen (val);
+  char *string = xmalloc (namelen + 1 + vallen + 1);
+  strcpy (string, name);
+  string[namelen] = '=';
+  strcpy (string + namelen + 1, val);
+  if (putenv (string) != 0)
+    xalloc_die ();
+}
+
+#if defined SYSLOG_SUCCESS || defined SYSLOG_FAILURE
+/* Log the fact that someone has run su to the user given by PW;
+   if SUCCESSFUL is true, they gave the correct password, etc.  */
+
+static void
+log_su (struct passwd const *pw, bool successful)
+{
+  const char *new_user, *old_user, *tty;
+
+# ifndef SYSLOG_NON_ROOT
+  if (pw->pw_uid)
+    return;
+# endif
+  new_user = pw->pw_name;
+  /* The utmp entry (via getlogin) is probably the best way to identify
+     the user, especially if someone su's from a su-shell.  */
+  old_user = getlogin ();
+  if (!old_user)
+    {
+      /* getlogin can fail -- usually due to lack of utmp entry.
+	 Resort to getpwuid.  */
+      struct passwd *pwd = getpwuid (getuid ());
+      old_user = (pwd ? pwd->pw_name : "");
+    }
+  tty = ttyname (STDERR_FILENO);
+  if (!tty)
+    tty = "none";
+  /* 4.2BSD openlog doesn't have the third parameter.  */
+  openlog (last_component (program_name), 0
+# ifdef LOG_AUTH
+	   , LOG_AUTH
+# endif
+	   );
+  syslog (LOG_NOTICE,
+# ifdef SYSLOG_NON_ROOT
+	  "%s(to %s) %s on %s",
+# else
+	  "%s%s on %s",
+# endif
+	  successful ? "" : "FAILED SU ",
+# ifdef SYSLOG_NON_ROOT
+	  new_user,
+# endif
+	  old_user, tty);
+  closelog ();
+}
+#endif
+
+/* Ask the user for a password.
+   Return true if the user gives the correct password for entry PW,
+   false if not.  Return true without asking for a password if run by UID 0
+   or if PW has an empty password.  */
+
+static bool
+correct_password (const struct passwd *pw)
+{
+  char *unencrypted, *encrypted, *correct;
+#if HAVE_GETSPNAM && HAVE_STRUCT_SPWD_SP_PWDP
+  /* Shadow passwd stuff for SVR3 and maybe other systems.  */
+  struct spwd *sp = getspnam (pw->pw_name);
+
+  endspent ();
+  if (sp)
+    correct = sp->sp_pwdp;
+  else
+#endif
+    correct = pw->pw_passwd;
+
+  if (getuid () == 0 || !correct || correct[0] == '\0')
+    return true;
+
+  unencrypted = getpass (_("Password:"));
+  if (!unencrypted)
+    {
+      error (0, 0, _("getpass: cannot open /dev/tty"));
+      return false;
+    }
+  encrypted = crypt (unencrypted, correct);
+  memset (unencrypted, 0, strlen (unencrypted));
+  return STREQ (encrypted, correct);
+}
+
+/* Update `environ' for the new shell based on PW, with SHELL being
+   the value for the SHELL environment variable.  */
+
+static void
+modify_environment (const struct passwd *pw, const char *shell)
+{
+  if (simulate_login)
+    {
+      /* Leave TERM unchanged.  Set HOME, SHELL, USER, LOGNAME, PATH.
+         Unset all other environment variables.  */
+      char const *term = getenv ("TERM");
+      if (term)
+	term = xstrdup (term);
+      environ = xmalloc ((6 + !!term) * sizeof (char *));
+      environ[0] = NULL;
+      if (term)
+	xsetenv ("TERM", term);
+      xsetenv ("HOME", pw->pw_dir);
+      xsetenv ("SHELL", shell);
+      xsetenv ("USER", pw->pw_name);
+      xsetenv ("LOGNAME", pw->pw_name);
+      xsetenv ("PATH", (pw->pw_uid
+			? DEFAULT_LOGIN_PATH
+			: DEFAULT_ROOT_LOGIN_PATH));
+    }
+  else
+    {
+      /* Set HOME, SHELL, and if not becoming a super-user,
+	 USER and LOGNAME.  */
+      if (change_environment)
+	{
+	  xsetenv ("HOME", pw->pw_dir);
+	  xsetenv ("SHELL", shell);
+	  if (pw->pw_uid)
+	    {
+	      xsetenv ("USER", pw->pw_name);
+	      xsetenv ("LOGNAME", pw->pw_name);
+	    }
+	}
+    }
+}
+
+/* Become the user and group(s) specified by PW.  */
+
+static void
+change_identity (const struct passwd *pw)
+{
+#ifdef HAVE_INITGROUPS
+  errno = 0;
+  if (initgroups (pw->pw_name, pw->pw_gid) == -1)
+    error (EXIT_FAILURE, errno, _("cannot set groups"));
+  endgrent ();
+#endif
+  if (setgid (pw->pw_gid))
+    error (EXIT_FAILURE, errno, _("cannot set group id"));
+  if (setuid (pw->pw_uid))
+    error (EXIT_FAILURE, errno, _("cannot set user id"));
+}
+
+/* Run SHELL, or DEFAULT_SHELL if SHELL is empty.
+   If COMMAND is nonzero, pass it to the shell with the -c option.
+   Pass ADDITIONAL_ARGS to the shell as more arguments; there
+   are N_ADDITIONAL_ARGS extra arguments.  */
+
+static void
+run_shell (char const *shell, char const *command, char **additional_args,
+	   size_t n_additional_args)
+{
+  size_t n_args = 1 + fast_startup + 2 * !!command + n_additional_args + 1;
+  char const **args = xnmalloc (n_args, sizeof *args);
+  size_t argno = 1;
+
+  if (simulate_login)
+    {
+      char *arg0;
+      char *shell_basename;
+
+      shell_basename = last_component (shell);
+      arg0 = xmalloc (strlen (shell_basename) + 2);
+      arg0[0] = '-';
+      strcpy (arg0 + 1, shell_basename);
+      args[0] = arg0;
+    }
+  else
+    args[0] = last_component (shell);
+  if (fast_startup)
+    args[argno++] = "-f";
+  if (command)
+    {
+      args[argno++] = "-c";
+      args[argno++] = command;
+    }
+  memcpy (args + argno, additional_args, n_additional_args * sizeof *args);
+  args[argno + n_additional_args] = NULL;
+  execv (shell, (char **) args);
+
+  {
+    int exit_status = (errno == ENOENT ? EXIT_ENOENT : EXIT_CANNOT_INVOKE);
+    error (0, errno, "%s", shell);
+    exit (exit_status);
+  }
+}
+
+/* Return true if SHELL is a restricted shell (one not returned by
+   getusershell), else false, meaning it is a standard shell.  */
+
+static bool
+restricted_shell (const char *shell)
+{
+  char *line;
+
+  setusershell ();
+  while ((line = getusershell ()) != NULL)
+    {
+      if (*line != '#' && STREQ (line, shell))
+	{
+	  endusershell ();
+	  return false;
+	}
+    }
+  endusershell ();
+  return true;
+}
+
+void
+usage (int status)
+{
+  if (status != EXIT_SUCCESS)
+    fprintf (stderr, _("Try `%s --help' for more information.\n"),
+	     program_name);
+  else
+    {
+      printf (_("Usage: %s [OPTION]... [-] [USER [ARG]...]\n"), program_name);
+      fputs (_("\
+Change the effective user id and group id to that of USER.\n\
+\n\
+  -, -l, --login               make the shell a login shell\n\
+  -c, --command=COMMAND        pass a single COMMAND to the shell with -c\n\
+  -f, --fast                   pass -f to the shell (for csh or tcsh)\n\
+  -m, --preserve-environment   do not reset environment variables\n\
+  -p                           same as -m\n\
+  -s, --shell=SHELL            run SHELL if /etc/shells allows it\n\
+"), stdout);
+      fputs (HELP_OPTION_DESCRIPTION, stdout);
+      fputs (VERSION_OPTION_DESCRIPTION, stdout);
+      fputs (_("\
+\n\
+A mere - implies -l.   If USER not given, assume root.\n\
+"), stdout);
+      emit_bug_reporting_address ();
+    }
+  exit (status);
+}
+
+int
+main (int argc, char **argv)
+{
+  int optc;
+  const char *new_user = DEFAULT_USER;
+  char *command = NULL;
+  char *shell = NULL;
+  struct passwd *pw;
+  struct passwd pw_copy;
+
+  initialize_main (&argc, &argv);
+  set_program_name (argv[0]);
+  setlocale (LC_ALL, "");
+  bindtextdomain (PACKAGE, LOCALEDIR);
+  textdomain (PACKAGE);
+
+  initialize_exit_failure (EXIT_FAILURE);
+  atexit (close_stdout);
+
+  fast_startup = false;
+  simulate_login = false;
+  change_environment = true;
+
+  while ((optc = getopt_long (argc, argv, "c:flmps:", longopts, NULL)) != -1)
+    {
+      switch (optc)
+	{
+	case 'c':
+	  command = optarg;
+	  break;
+
+	case 'f':
+	  fast_startup = true;
+	  break;
+
+	case 'l':
+	  simulate_login = true;
+	  break;
+
+	case 'm':
+	case 'p':
+	  change_environment = false;
+	  break;
+
+	case 's':
+	  shell = optarg;
+	  break;
+
+	case_GETOPT_HELP_CHAR;
+
+	case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
+
+	default:
+	  usage (EXIT_FAILURE);
+	}
+    }
+
+  if (optind < argc && STREQ (argv[optind], "-"))
+    {
+      simulate_login = true;
+      ++optind;
+    }
+  if (optind < argc)
+    new_user = argv[optind++];
+
+  pw = getpwnam (new_user);
+  if (! (pw && pw->pw_name && pw->pw_name[0] && pw->pw_dir && pw->pw_dir[0]
+	 && pw->pw_passwd))
+    error (EXIT_FAILURE, 0, _("user %s does not exist"), new_user);
+
+  /* Make a copy of the password information and point pw at the local
+     copy instead.  Otherwise, some systems (e.g. GNU/Linux) would clobber
+     the static data through the getlogin call from log_su.
+     Also, make sure pw->pw_shell is a nonempty string.
+     It may be NULL when NEW_USER is a username that is retrieved via NIS (YP),
+     but that doesn't have a default shell listed.  */
+  pw_copy = *pw;
+  pw = &pw_copy;
+  pw->pw_name = xstrdup (pw->pw_name);
+  pw->pw_passwd = xstrdup (pw->pw_passwd);
+  pw->pw_dir = xstrdup (pw->pw_dir);
+  pw->pw_shell = xstrdup (pw->pw_shell && pw->pw_shell[0]
+			  ? pw->pw_shell
+			  : DEFAULT_SHELL);
+  endpwent ();
+
+  if (!correct_password (pw))
+    {
+#ifdef SYSLOG_FAILURE
+      log_su (pw, false);
+#endif
+      error (EXIT_FAILURE, 0, _("incorrect password"));
+    }
+#ifdef SYSLOG_SUCCESS
+  else
+    {
+      log_su (pw, true);
+    }
+#endif
+
+  if (!shell && !change_environment)
+    shell = getenv ("SHELL");
+  if (shell && getuid () != 0 && restricted_shell (pw->pw_shell))
+    {
+      /* The user being su'd to has a nonstandard shell, and so is
+	 probably a uucp account or has restricted access.  Don't
+	 compromise the account by allowing access with a standard
+	 shell.  */
+      error (0, 0, _("using restricted shell %s"), pw->pw_shell);
+      shell = NULL;
+    }
+  shell = xstrdup (shell ? shell : pw->pw_shell);
+  modify_environment (pw, shell);
+
+  change_identity (pw);
+  if (simulate_login && chdir (pw->pw_dir) != 0)
+    error (0, errno, _("warning: cannot change directory to %s"), pw->pw_dir);
+
+  run_shell (shell, command, argv + optind, MAX (0, argc - optind));
+}