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+/* list.c - Functions for manipulating linked lists of objects. */
+
+/* Copyright (C) 1996-2009 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 (HAVE_UNISTD_H)
+# ifdef _MINIX
+# include <sys/types.h>
+# endif
+# include <unistd.h>
+#endif
+
+#include "shell.h"
+
+/* A global variable which acts as a sentinel for an `error' list return. */
+GENERIC_LIST global_error_list;
+
+#ifdef INCLUDE_UNUSED
+/* Call FUNCTION on every member of LIST, a generic list. */
+void
+list_walk (list, function)
+ GENERIC_LIST *list;
+ sh_glist_func_t *function;
+{
+ for ( ; list; list = list->next)
+ if ((*function) (list) < 0)
+ return;
+}
+
+/* Call FUNCTION on every string in WORDS. */
+void
+wlist_walk (words, function)
+ WORD_LIST *words;
+ sh_icpfunc_t *function;
+{
+ for ( ; words; words = words->next)
+ if ((*function) (words->word->word) < 0)
+ return;
+}
+#endif /* INCLUDE_UNUSED */
+
+/* Reverse the chain of structures in LIST. Output the new head
+ of the chain. You should always assign the output value of this
+ function to something, or you will lose the chain. */
+GENERIC_LIST *
+list_reverse (list)
+ GENERIC_LIST *list;
+{
+ register GENERIC_LIST *next, *prev;
+
+ for (prev = (GENERIC_LIST *)NULL; list; )
+ {
+ next = list->next;
+ list->next = prev;
+ prev = list;
+ list = next;
+ }
+ return (prev);
+}
+
+/* Return the number of elements in LIST, a generic list. */
+int
+list_length (list)
+ GENERIC_LIST *list;
+{
+ register int i;
+
+ for (i = 0; list; list = list->next, i++);
+ return (i);
+}
+
+/* Append TAIL to HEAD. Return the header of the list. */
+GENERIC_LIST *
+list_append (head, tail)
+ GENERIC_LIST *head, *tail;
+{
+ register GENERIC_LIST *t_head;
+
+ if (head == 0)
+ return (tail);
+
+ for (t_head = head; t_head->next; t_head = t_head->next)
+ ;
+ t_head->next = tail;
+ return (head);
+}
+
+#ifdef INCLUDE_UNUSED
+/* Delete the element of LIST which satisfies the predicate function COMPARER.
+ Returns the element that was deleted, so you can dispose of it, or -1 if
+ the element wasn't found. COMPARER is called with the list element and
+ then ARG. Note that LIST contains the address of a variable which points
+ to the list. You might call this function like this:
+
+ SHELL_VAR *elt = list_remove (&variable_list, check_var_has_name, "foo");
+ dispose_variable (elt);
+*/
+GENERIC_LIST *
+list_remove (list, comparer, arg)
+ GENERIC_LIST **list;
+ Function *comparer;
+ char *arg;
+{
+ register GENERIC_LIST *prev, *temp;
+
+ for (prev = (GENERIC_LIST *)NULL, temp = *list; temp; prev = temp, temp = temp->next)
+ {
+ if ((*comparer) (temp, arg))
+ {
+ if (prev)
+ prev->next = temp->next;
+ else
+ *list = temp->next;
+ return (temp);
+ }
+ }
+ return ((GENERIC_LIST *)&global_error_list);
+}
+#endif