/* flags.c -- Everything about flags except the `set' command.  That
   is in builtins.c */

/* Copyright (C) 1987,1989 Free Software Foundation, Inc.

This file is part of GNU Bash, the Bourne Again SHell.

Bash 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 1, or (at your option) any later
version.

Bash 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 Bash; see the file COPYING.  If not, write to the Free Software
Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */

/* Flags hacking. */

#include "shell.h"
#include "flags.h"

/* **************************************************************** */
/*								    */
/*			The Standard Sh Flags.			    */
/*								    */
/* **************************************************************** */

/* Non-zero means automatically mark variables which are modified or created
   as auto export variables. */
int mark_modified_vars = 0;

/* Non-zero causes asynchronous job notification.  Otherwise, job state
   notification only takes place just before a primary prompt is printed. */
int asynchronous_notification = 0;

/* Non-zero means exit immediately if a command exits with a non-zero
   exit status. */
int exit_immediately_on_error = 0;

/* Non-zero means disable filename globbing. */
int disallow_filename_globbing = 0;

/* Non-zero means to locate and remember function commands as functions are
   defined.  Function commands are normally located when the function is
   executed. */
int locate_commands_in_functions = 0;

/* Non-zero means that all keyword arguments are placed into the environment
   for a command, not just those that appear on the line before the command
   name. */
int place_keywords_in_env = 0;

/* Non-zero means read commands, but don't execute tham.  This is useful
   for debugging shell scripts that should do something hairy and possibly
   desctructive. */
int read_but_dont_execute = 0;

/* Non-zero means end of file is after one command. */
int just_one_command = 0;

/* Non-zero means don't overwrite existing files while doing redirections. */
int noclobber = 0;

/* Non-zero means trying to get the value of $i where $i is undefined
   causes an error, instead of a null substitution. */
int unbound_vars_is_error = 0;

/* Non-zero means type out input lines after you read them. */
int echo_input_at_read = 0;

/* Non-zero means type out the command definition after reading, but
   before executing. */
int echo_command_at_execute = 0;

/* Non-zero means turn on the job control features. */
int jobs_m_flag = 0;

/* Non-zero means this shell is interactive, even if running under a
   pipe. */
int forced_interactive = 0;

/* **************************************************************** */
/*								    */
/*		     Non-Standard Flags Follow Here.		    */
/*								    */
/* **************************************************************** */


/* Non-zero means do lexical scoping in the body of a FOR command. */
int lexical_scoping = 0;

/* Non-zero means no such thing as invisible variables. */
int no_invisible_vars = 0;

/* Non-zero means don't look up or remember command names in a hash table, */
int hashing_disabled = 0;

#if defined (HISTORY)
/* Non-zero means that we are doing history expansion.  The default.
   This means !22 gets the 22nd line of history. */
int history_expansion = 1;
#endif /* HISTORY */

/* Non-zero means that we allow comments to appear in interactive commands. */
#if defined (INTERACTIVE_COMMENTS)
int interactive_comments = 1;
#else
int interactive_comments = 0;
#endif /* INTERACTIVE_COMMENTS */

#if defined (RESTRICTED_SHELL)
/* Non-zero means that this shell is `restricted'.  A restricted shell
   disallows: changing directories, command or path names containing `/',
   unsetting or resetting the values of $PATH and $SHELL, and any type of
   output redirection. */
int restricted = 0;
#endif /* RESTRICTED_SHELL */

/* Non-zero means that this shell is running in `privileged' mode.  This
   mode is entered on startup if the real and effective uids or gids
   differ. */
int privileged_mode = 0;

/* **************************************************************** */
/*								    */
/*			The Flags ALIST.			    */
/*								    */
/* **************************************************************** */

struct flags_alist shell_flags[] = {

  /* Standard sh flags. */
  { "a", &mark_modified_vars },
#if defined (JOB_CONTROL)
  { "b", &asynchronous_notification },
#endif /* JOB_CONTROL */
  { "e", &exit_immediately_on_error },
  { "f", &disallow_filename_globbing },
  { "h", &locate_commands_in_functions }, /* Oh, yeah, good mnemonic. */
  { "i", &forced_interactive },
  { "k", &place_keywords_in_env },
#if defined (JOB_CONTROL)
  { "m", &jobs_m_flag },
#endif /* JOB_CONTROL */
  { "n", &read_but_dont_execute },
  { "p", &privileged_mode },
#if defined (RESTRICTED_SHELL)
  { "r", &restricted },
#endif /* RESTRICTED_SHELL */
  { "t", &just_one_command },
  { "u", &unbound_vars_is_error },
  { "v", &echo_input_at_read },
  { "x", &echo_command_at_execute },
  { "C", &noclobber },

  /* New flags that control non-standard things. */
  { "l", &lexical_scoping },
  { "I", &no_invisible_vars },

  /* I want `h', but locate_commands_in_functions has it.  Great. */
  { "d", &hashing_disabled },

#if defined (HISTORY)
  /* Once again, we don't have the right mnemonic. */
  { "H", &history_expansion },
#endif /* HISTORY */

  {(char *)NULL, (int *)NULL}
};


int *
find_flag (name)
     char *name;
{
  int i = 0;
  while (shell_flags[i].name)
    {
      if (strcmp (shell_flags[i].name, name) == 0)
	return (shell_flags[i].value);
      i++;
    }
  return ((int *)FLAG_ERROR);
}

/* Change the state of a flag, and return it's original value, or return
   FLAG_ERROR if there is no flag called NAME.  ON_OR_OFF should be one
   of FLAG_ON or FLAG_OFF. */

/* With FLAG being a character. */
change_flag_char (flag, on_or_off)
     int flag;
     int on_or_off;
{
  char name[2];
  name[0] = flag; name[1] = '\0';
  return (change_flag (name, on_or_off));
}

/* With FLAG being a string. */
change_flag (flag, on_or_off)
  char *flag;
  int on_or_off;
{
  int *value = find_flag (flag);
  int old_value;

#if defined (RESTRICTED_SHELL)
  /* Don't allow "set +r" in a shell which is `restricted'. */
  if (restricted && flag[0] == 'r' && on_or_off == FLAG_OFF)
    return (FLAG_ERROR);
#endif /* RESTRICTED_SHELL */

  if (value == (int *)FLAG_ERROR)
    return (FLAG_ERROR);
  else
    old_value = *value;

  if (on_or_off == FLAG_ON)
    *value = 1;
  else
    {
      if (on_or_off == FLAG_OFF)
	*value = 0;
      else
	return (FLAG_ERROR);
    }

#if defined (JOB_CONTROL)
  /* Special hack for the -m flag. */
  if (value == &jobs_m_flag)
    {
      extern set_job_control ();
      set_job_control (on_or_off == '-');
    }
#endif /* JOB_CONTROL */

  /* The -p flag needs a special case as well. */
  if (value == &privileged_mode)
    {
      if (on_or_off == '+')
	{
	  setuid (current_user.uid);
	  setgid (current_user.gid);
	  current_user.euid = current_user.uid;
	  current_user.egid = current_user.gid;
	}
    }
    
  return (old_value);
}

/* Return a string which is the names of all the currently
   set shell flags. */
char *
which_set_flags ()
{
  char *temp =
    (char *)xmalloc (1 + sizeof (shell_flags) / (2 * sizeof (char *)));

  int index, string_index = 0;

  for (index = 0; shell_flags[index].name; index++)
    if (*(shell_flags[index].value))
      temp[string_index++] = *(shell_flags[index].name);

  temp[string_index] = '\0';
  return (temp);
}