arrayfunc.c

android-w.song.android.widget

/* arrayfunc.c -- High-level array functions used by other parts of the shell. */

/* Copyright (C) 2001-2010 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 3 of the License, 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.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "config.h"

#if defined (ARRAY_VARS)

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

#include "bashintl.h"

#include "shell.h"
#include "pathexp.h"

#include "shmbutil.h"

#include "builtins/common.h"

extern char *this_command_name;
extern int last_command_exit_value;
extern int array_needs_making;

static SHELL_VAR *bind_array_var_internal __P((SHELL_VAR *, arrayind_t, char *, char *, int));

static char *quote_assign __P((const char *));
static void quote_array_assignment_chars __P((WORD_LIST *));
static char *array_value_internal __P((char *, int, int, int *, arrayind_t *));

/* Standard error message to use when encountering an invalid array subscript */
const char * const bash_badsub_errmsg = N_("bad array subscript");

/* **************************************************************** */
/*								    */
/*  Functions to manipulate array variables and perform assignments */
/*								    */
/* **************************************************************** */

/* Convert a shell variable to an array variable.  The original value is
   saved as array[0]. */
SHELL_VAR *
convert_var_to_array (var)
     SHELL_VAR *var;
{
  char *oldval;
  ARRAY *array;

  oldval = value_cell (var);
  array = array_create ();
  if (oldval)
    array_insert (array, 0, oldval);

  FREE (value_cell (var));
  var_setarray (var, array);

  /* these aren't valid anymore */
  var->dynamic_value = (sh_var_value_func_t *)NULL;
  var->assign_func = (sh_var_assign_func_t *)NULL;

  INVALIDATE_EXPORTSTR (var);
  if (exported_p (var))
    array_needs_making++;

  VSETATTR (var, att_array);
  VUNSETATTR (var, att_invisible);

  return var;
}

/* Convert a shell variable to an array variable.  The original value is
   saved as array[0]. */
SHELL_VAR *
convert_var_to_assoc (var)
     SHELL_VAR *var;
{
  char *oldval;
  HASH_TABLE *hash;

  oldval = value_cell (var);
  hash = assoc_create (0);
  if (oldval)
    assoc_insert (hash, savestring ("0"), oldval);

  FREE (value_cell (var));
  var_setassoc (var, hash);

  /* these aren't valid anymore */
  var->dynamic_value = (sh_var_value_func_t *)NULL;
  var->assign_func = (sh_var_assign_func_t *)NULL;

  INVALIDATE_EXPORTSTR (var);
  if (exported_p (var))
    array_needs_making++;

  VSETATTR (var, att_assoc);
  VUNSETATTR (var, att_invisible);

  return var;
}

static SHELL_VAR *
bind_array_var_internal (entry, ind, key, value, flags)
     SHELL_VAR *entry;
     arrayind_t ind;
     char *key;
     char *value;
     int flags;
{
  SHELL_VAR *dentry;
  char *newval;

  /* If we're appending, we need the old value of the array reference, so
     fake out make_variable_value with a dummy SHELL_VAR */
  if (flags & ASS_APPEND)
    {
      dentry = (SHELL_VAR *)xmalloc (sizeof (SHELL_VAR));
      dentry->name = savestring (entry->name);
      if (assoc_p (entry))
	newval = assoc_reference (assoc_cell (entry), key);
      else
	newval = array_reference (array_cell (entry), ind);
      if (newval)
	dentry->value = savestring (newval);
      else
	{
	  dentry->value = (char *)xmalloc (1);
	  dentry->value[0] = '\0';
	}
      dentry->exportstr = 0;
      dentry->attributes = entry->attributes & ~(att_array|att_assoc|att_exported);
      /* Leave the rest of the members uninitialized; the code doesn't look
	 at them. */
      newval = make_variable_value (dentry, value, flags);	 
      dispose_variable (dentry);
    }
  else
    newval = make_variable_value (entry, value, flags);

  if (entry->assign_func)
    (*entry->assign_func) (entry, newval, ind, key);
  else if (assoc_p (entry))
    assoc_insert (assoc_cell (entry), key, newval);
  else
    array_insert (array_cell (entry), ind, newval);
  FREE (newval);

  return (entry);
}

/* Perform an array assignment name[ind]=value.  If NAME already exists and
   is not an array, and IND is 0, perform name=value instead.  If NAME exists
   and is not an array, and IND is not 0, convert it into an array with the
   existing value as name[0].

   If NAME does not exist, just create an array variable, no matter what
   IND's value may be. */
SHELL_VAR *
bind_array_variable (name, ind, value, flags)
     char *name;
     arrayind_t ind;
     char *value;
     int flags;
{
  SHELL_VAR *entry;

  entry = var_lookup (name, shell_variables);

  if (entry == (SHELL_VAR *) 0)
    entry = make_new_array_variable (name);
  else if (readonly_p (entry) || noassign_p (entry))
    {
      if (readonly_p (entry))
	err_readonly (name);
      return (entry);
    }
  else if (array_p (entry) == 0)
    entry = convert_var_to_array (entry);

  /* ENTRY is an array variable, and ARRAY points to the value. */
  return (bind_array_var_internal (entry, ind, 0, value, flags));
}

SHELL_VAR *
bind_array_element (entry, ind, value, flags)
     SHELL_VAR *entry;
     arrayind_t ind;
     char *value;
     int flags;
{
  return (bind_array_var_internal (entry, ind, 0, value, flags));
}
                    
SHELL_VAR *
bind_assoc_variable (entry, name, key, value, flags)
     SHELL_VAR *entry;
     char *name;
     char *key;
     char *value;
     int flags;
{
  SHELL_VAR *dentry;
  char *newval;

  if (readonly_p (entry) || noassign_p (entry))
    {
      if (readonly_p (entry))
	err_readonly (name);
      return (entry);
    }

  return (bind_array_var_internal (entry, 0, key, value, flags));
}

/* Parse NAME, a lhs of an assignment statement of the form v[s], and
   assign VALUE to that array element by calling bind_array_variable(). */
SHELL_VAR *
assign_array_element (name, value, flags)
     char *name, *value;
     int flags;
{
  char *sub, *vname, *akey;
  arrayind_t ind;
  int sublen;
  SHELL_VAR *entry;

  vname = array_variable_name (name, &sub, &sublen);

  if (vname == 0)
    return ((SHELL_VAR *)NULL);

  if ((ALL_ELEMENT_SUB (sub[0]) && sub[1] == ']') || (sublen <= 1))
    {
      free (vname);
      err_badarraysub (name);
      return ((SHELL_VAR *)NULL);
    }

  entry = find_variable (vname);

  if (entry && assoc_p (entry))
    {
      sub[sublen-1] = '\0';
      akey = expand_assignment_string_to_string (sub, 0);	/* [ */
      sub[sublen-1] = ']';
      if (akey == 0 || *akey == 0)
	{
	  free (vname);
	  err_badarraysub (name);
	  return ((SHELL_VAR *)NULL);
	}
      entry = bind_assoc_variable (entry, vname, akey, value, flags);
    }
  else
    {
      ind = array_expand_index (sub, sublen);
      if (ind < 0)
	{
	  free (vname);
	  err_badarraysub (name);
	  return ((SHELL_VAR *)NULL);
	}
      entry = bind_array_variable (vname, ind, value, flags);
    }

  free (vname);
  return (entry);
}

/* Find the array variable corresponding to NAME.  If there is no variable,
   create a new array variable.  If the variable exists but is not an array,
   convert it to an indexed array.  If FLAGS&1 is non-zero, an existing
   variable is checked for the readonly or noassign attribute in preparation
   for assignment (e.g., by the `read' builtin).  If FLAGS&2 is non-zero, we
   create an associative array. */
SHELL_VAR *
find_or_make_array_variable (name, flags)
     char *name;
     int flags;
{
  SHELL_VAR *var;

  var = find_variable (name);

  if (var == 0)
    var = (flags & 2) ? make_new_assoc_variable (name) : make_new_array_variable (name);
  else if ((flags & 1) && (readonly_p (var) || noassign_p (var)))
    {
      if (readonly_p (var))
	err_readonly (name);
      return ((SHELL_VAR *)NULL);
    }
  else if ((flags & 2) && array_p (var))
    {
      report_error (_("%s: cannot convert indexed to associative array"), name);
      return ((SHELL_VAR *)NULL);
    }
  else if (array_p (var) == 0 && assoc_p (var) == 0)
    var = convert_var_to_array (var);

  return (var);
}
  
/* Perform a compound assignment statement for array NAME, where VALUE is
   the text between the parens:  NAME=( VALUE ) */
SHELL_VAR *
assign_array_from_string (name, value, flags)
     char *name, *value;
     int flags;
{
  SHELL_VAR *var;
  int vflags;

  vflags = 1;
  if (flags & ASS_MKASSOC)
    vflags |= 2;

  var = find_or_make_array_variable (name, vflags);
  if (var == 0)
    return ((SHELL_VAR *)NULL);

  return (assign_array_var_from_string (var, value, flags));
}

/* Sequentially assign the indices of indexed array variable VAR from the
   words in LIST. */
SHELL_VAR *
assign_array_var_from_word_list (var, list, flags)
     SHELL_VAR *var;
     WORD_LIST *list;
     int flags;
{
  register arrayind_t i;
  register WORD_LIST *l;
  ARRAY *a;

  a = array_cell (var);
  i = (flags & ASS_APPEND) ? array_max_index (a) + 1 : 0;

  for (l = list; l; l = l->next, i++)
    if (var->assign_func)
      (*var->assign_func) (var, l->word->word, i, 0);
    else
      array_insert (a, i, l->word->word);
  return var;
}

WORD_LIST *
expand_compound_array_assignment (var, value, flags)
     SHELL_VAR *var;
     char *value;
     int flags;
{
  WORD_LIST *list, *nlist;
  char *val;
  int ni;

  /* I don't believe this condition is ever true any more. */
  if (*value == '(')	/*)*/
    {
      ni = 1;
      val = extract_array_assignment_list (value, &ni);
      if (val == 0)
	return (WORD_LIST *)NULL;
    }
  else
    val = value;

  /* Expand the value string into a list of words, performing all the
     shell expansions including pathname generation and word splitting. */
  /* First we split the string on whitespace, using the shell parser
     (ksh93 seems to do this). */
  list = parse_string_to_word_list (val, 1, "array assign");

  /* If we're using [subscript]=value, we need to quote each [ and ] to
     prevent unwanted filename expansion. */
  if (list)
    quote_array_assignment_chars (list);

  /* Now that we've split it, perform the shell expansions on each
     word in the list. */
  nlist = list ? expand_words_no_vars (list) : (WORD_LIST *)NULL;

  dispose_words (list);

  if (val != value)
    free (val);

  return nlist;
}

/* Callers ensure that VAR is not NULL */
void
assign_compound_array_list (var, nlist, flags)
     SHELL_VAR *var;
     WORD_LIST *nlist;
     int flags;
{
  ARRAY *a;
  HASH_TABLE *h;
  WORD_LIST *list;
  char *w, *val, *nval;
  int len, iflags;
  arrayind_t ind, last_ind;
  char *akey;

  a = (var && array_p (var)) ? array_cell (var) : (ARRAY *)0;
  h = (var && assoc_p (var)) ? assoc_cell (var) : (HASH_TABLE *)0;

  akey = (char *)0;
  ind = 0;

  /* Now that we are ready to assign values to the array, kill the existing
     value. */
  if ((flags & ASS_APPEND) == 0)
    {
      if (a && array_p (var))
	array_flush (a);
      else if (h && assoc_p (var))
	assoc_flush (h);
    }

  last_ind = (a && (flags & ASS_APPEND)) ? array_max_index (a) + 1 : 0;

  for (list = nlist; list; list = list->next)
    {
      iflags = flags;
      w = list->word->word;

      /* We have a word of the form [ind]=value */
      if ((list->word->flags & W_ASSIGNMENT) && w[0] == '[')
	{
	  len = skipsubscript (w, 0, (var && assoc_p (var) != 0));

	  /* XXX - changes for `+=' */
 	  if (w[len] != ']' || (w[len+1] != '=' && (w[len+1] != '+' || w[len+2] != '=')))
	    {
	      if (assoc_p (var))
		{
		  err_badarraysub (w);
		  continue;
		}
	      nval = make_variable_value (var, w, flags);
	      if (var->assign_func)
		(*var->assign_func) (var, nval, last_ind, 0);
	      else
		array_insert (a, last_ind, nval);
	      FREE (nval);
	      last_ind++;
	      continue;
	    }

	  if (len == 1)
	    {
	      err_badarraysub (w);
	      continue;
	    }

	  if (ALL_ELEMENT_SUB (w[1]) && len == 2)
	    {
	      if (assoc_p (var))
		report_error (_("%s: invalid associative array key"), w);
	      else
		report_error (_("%s: cannot assign to non-numeric index"), w);
	      continue;
	    }

	  if (array_p (var))
	    {
	      ind = array_expand_index (w + 1, len);
	      if (ind < 0)
		{
		  err_badarraysub (w);
		  continue;
		}

	      last_ind = ind;
	    }
	  else if (assoc_p (var))
	    {
	      akey = substring (w, 1, len);
	      if (akey == 0 || *akey == 0)
		{
		  err_badarraysub (w);
		  continue;
		}
	    }

	  /* XXX - changes for `+=' -- just accept the syntax.  ksh93 doesn't do this */
	  if (w[len + 1] == '+' && w[len + 2] == '=')
	    {
	      iflags |= ASS_APPEND;
	      val = w + len + 3;
	    }
	  else
	    val = w + len + 2;
	}
      else if (assoc_p (var))
	{
	  report_error (_("%s: %s: must use subscript when assigning associative array"), var->name, w);
	  continue;
	}
      else		/* No [ind]=value, just a stray `=' */