This file is setattr.def, from which is created setattr.c.
It implements the builtins "export" and "readonly", in Bash.

Copyright (C) 1987, 1989, 1991 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.

$PRODUCES setattr.c

#include <config.h>

#if defined (HAVE_UNISTD_H)
#  include <unistd.h>
#endif

#include <stdio.h>
#include "../bashansi.h"

#include "../shell.h"
#include "common.h"
#include "bashgetopt.h"

extern int posixly_correct;
extern int array_needs_making;
extern char *this_command_name;
extern Function *this_shell_builtin;

#ifdef ARRAY_VARS
extern int declare_builtin ();
#endif

#define READONLY_OR_EXPORT \
  (this_shell_builtin == readonly_builtin || this_shell_builtin == export_builtin)

$BUILTIN export
$FUNCTION export_builtin
$SHORT_DOC export [-nf] [name ...] or export -p
NAMEs are marked for automatic export to the environment of
subsequently executed commands.  If the -f option is given,
the NAMEs refer to functions.  If no NAMEs are given, or if `-p'
is given, a list of all names that are exported in this shell is
printed.  An argument of `-n' says to remove the export property
from subsequent NAMEs.  An argument of `--' disables further option
processing.
$END

/* For each variable name in LIST, make that variable appear in the
   environment passed to simple commands.  If there is no LIST, then
   print all such variables.  An argument of `-n' says to remove the
   exported attribute from variables named in LIST.  An argument of
  -f indicates that the names present in LIST refer to functions. */
int
export_builtin (list)
     register WORD_LIST *list;
{
  return (set_or_show_attributes (list, att_exported, 0));
}

$BUILTIN readonly
$FUNCTION readonly_builtin
$SHORT_DOC readonly [-anf] [name ...] or readonly -p
The given NAMEs are marked readonly and the values of these NAMEs may
not be changed by subsequent assignment.  If the -f option is given,
then functions corresponding to the NAMEs are so marked.  If no
arguments are given, or if `-p' is given, a list of all readonly names
is printed.  An argument of `-n' says to remove the readonly property
from subsequent NAMEs.  The `-a' option means to treat each NAME as
an array variable.  An argument of `--' disables further option
processing.
$END

/* For each variable name in LIST, make that variable readonly.  Given an
   empty LIST, print out all existing readonly variables. */
int
readonly_builtin (list)
     register WORD_LIST *list;
{
  return (set_or_show_attributes (list, att_readonly, 0));
}

/* For each variable name in LIST, make that variable have the specified
   ATTRIBUTE.  An arg of `-n' says to remove the attribute from the the
   remaining names in LIST. */
int
set_or_show_attributes (list, attribute, nodefs)
     register WORD_LIST *list;
     int attribute, nodefs;
{
  register SHELL_VAR *var;
  int assign, undo, functions_only, arrays_only, any_failed, assign_error, opt;
  char *name;
#if defined (ARRAY_VARS)
  WORD_LIST *nlist, *tlist;
  WORD_DESC *w;
#endif

  undo = functions_only = arrays_only = any_failed = assign_error = 0;
  /* Read arguments from the front of the list. */
  reset_internal_getopt ();
  while ((opt = internal_getopt (list, "anfp")) != -1)
    {
      switch (opt)
	{
	  case 'n':
	    undo = 1;
	    break;
	  case 'f':
	    functions_only = 1;
	    break;
#if defined (ARRAY_VARS)
	  case 'a':
	     arrays_only = 1;
	     break;
#endif
	  case 'p':
	    break;
	  default:
	    builtin_usage ();
	    return (EX_USAGE);
	}
    }
  list = loptend;

  if (list)
    {
      if (attribute & att_exported)
	array_needs_making = 1;

      /* Cannot undo readonly status, silently disallowed. */
      if (undo && (attribute & att_readonly))
	attribute &= ~att_readonly;

      while (list)
	{
	  name = list->word->word;

	  if (functions_only)		/* xxx -f name */
	    {
	      var = find_function (name);
	      if (var == 0)
		{
		  builtin_error ("%s: not a function", name);
		  any_failed++;
		}
	      else
		SETVARATTR (var, attribute, undo);

	      list = list->next;
	      continue;
	    }

	  /* xxx [-np] name[=value] */
	  assign = assignment (name);

          if (assign)
	    name[assign] = '\0';

	  if (legal_identifier (name) == 0)
	    {
	      builtin_error ("`%s': not a valid identifier", name);
	      if (assign)
		assign_error++;
	      else
		any_failed++;
	      list = list->next;
	      continue;
	    }

	  if (assign)	/* xxx [-np] name=value */
	    {
	      name[assign] = '=';
#if defined (ARRAY_VARS)
	      /* Let's try something here.  Turn readonly -a xxx=yyy into
		 declare -ra xxx=yyy and see what that gets us. */
	      if (arrays_only)
		{
		  tlist = list->next;
		  list->next = (WORD_LIST *)NULL;
		  w = make_word ("-ra");
		  nlist = make_word_list (w, list);
		  opt = declare_builtin (nlist);
		  if (opt != EXECUTION_SUCCESS)
		    assign_error++;
		  list->next = tlist;
		  dispose_word (w);
		  free (nlist);
		}
	      else
#endif
	      /* This word has already been expanded once with command
		 and parameter expansion.  Call do_assignment_no_expand (),
		 which does not do command or parameter substitution.  If
		 the assignment is not performed correctly, flag an error. */
	      if (do_assignment_no_expand (name) == 0)
		assign_error++;
	      name[assign] = '\0';
	    }

	  set_var_attribute (name, attribute, undo);
	  list = list->next;
	}
    }
  else
    {
      SHELL_VAR **variable_list;
      register int i;

      if ((attribute & att_function) || functions_only)
	{
	  variable_list = all_shell_functions ();
	  if (attribute != att_function)
	    attribute &= ~att_function;	/* so declare -xf works, for example */
	}
      else
	variable_list = all_shell_variables ();

#if defined (ARRAY_VARS)
      if (attribute & att_array)
        {
          arrays_only++;
          if (attribute != att_array)
	    attribute &= ~att_array;
        }
#endif

      if (variable_list)
	{
	  for (i = 0; var = variable_list[i]; i++)
	    {
#if defined (ARRAY_VARS)
	      if (arrays_only && array_p (var) == 0)
	        continue;
#endif
	      if ((var->attributes & attribute) && invisible_p (var) == 0)
		show_var_attributes (var, READONLY_OR_EXPORT, nodefs);
	    }
	  free (variable_list);
	}
    }

  return (assign_error ? EX_BADASSIGN
		       : ((any_failed == 0) ? EXECUTION_SUCCESS
  					    : EXECUTION_FAILURE));
}

/* Show the attributes for shell variable VAR.  If NODEFS is non-zero,
   don't show function definitions along with the name.  If PATTR is
   non-zero, it indicates we're being called from `export' or `readonly'.
   In POSIX mode, this prints the name of the calling builtin (`export'
   or `readonly') instead of `declare', and doesn't print function defs
   when called by `export' or `readonly'. */
int
show_var_attributes (var, pattr, nodefs)
     SHELL_VAR *var;
     int pattr, nodefs;
{
  char flags[6], *x;
  int i;

  i = 0;

  /* pattr == 0 means we are called from `declare'. */
  if (pattr == 0 || posixly_correct == 0)
    {
#if defined (ARRAY_VARS)
      if (array_p (var))
	flags[i++] = 'a';
#endif

      if (function_p (var))
        flags[i++] = 'f';

      if (integer_p (var))
        flags[i++] = 'i';

      if (readonly_p (var))
        flags[i++] = 'r';

      if (exported_p (var))
        flags[i++] = 'x';
    }
  else
    {
#if defined (ARRAY_VARS)
      if (array_p (var))
	flags[i++] = 'a';
#endif

      if (function_p (var))
        flags[i++] = 'f';
    }

  flags[i] = '\0';

  if (pattr == 0 || posixly_correct == 0)
    printf ("declare -%s ", i ? flags : "-");
  else if (i)
    printf ("%s -%s ", this_command_name, flags);
  else
    printf ("%s ", this_command_name);

#if defined (ARRAY_VARS)
 if (array_p (var))
    print_array_assignment (var, 1);
  else
#endif
  /* force `readline' and `export' to not print out function definitions
     when in POSIX mode. */
  if (nodefs || (function_p (var) && pattr != 0 && posixly_correct))
    printf ("%s\n", var->name);
  else if (function_p (var))
    printf ("%s\n", named_function_string (var->name, function_cell (var), 1));
  else
    {
      x = double_quote (value_cell (var));
      printf ("%s=%s\n", var->name, x);
      free (x);
    }
  return (0);
}

int
show_name_attributes (name, nodefs)
     char *name;
     int nodefs;
{
  SHELL_VAR *var;

  var = find_tempenv_variable (name);
  if (var == 0)
    var = find_variable (name);

  if (var && invisible_p (var) == 0)
    {
      show_var_attributes (var, READONLY_OR_EXPORT, nodefs);
      return (0);
    }
  else
    return (1);
}

void
set_var_attribute (name, attribute, undo)
     char *name;
     int attribute, undo;
{
  SHELL_VAR *var, *tv;

  if (undo)
    var = find_variable (name);
  else
    {
      if (tv = find_tempenv_variable (name))
	{
	  var = bind_variable (tv->name, tv->value);
	  dispose_variable (tv);
	}
      else
	var = find_variable (name);

      if (var == 0)
	{
	  var = bind_variable (name, (char *)NULL);
	  var->attributes |= att_invisible;
	}
    }

  if (var)
    SETVARATTR (var, attribute, undo);

  if (var && ((var->attributes & att_exported) || (attribute & att_exported)))
    array_needs_making++;	/* XXX */
}