135 lines
3.4 KiB
C
135 lines
3.4 KiB
C
/* list.c - Functions for manipulating linked lists of objects. */
|
|
|
|
/* Copyright (C) 1996
|
|
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 2, 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. */
|
|
|
|
#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
|
|
map_over_list (list, function)
|
|
GENERIC_LIST *list;
|
|
Function *function;
|
|
{
|
|
for ( ; list; list = list->next)
|
|
(*function) (list);
|
|
}
|
|
|
|
/* Call FUNCTION on every string in WORDS. */
|
|
void
|
|
map_over_words (words, function)
|
|
WORD_LIST *words;
|
|
Function *function;
|
|
{
|
|
for ( ; words; words = words->next)
|
|
(*function) (words->word->word);
|
|
}
|
|
#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 *
|
|
reverse_list (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 = delete_element (&variable_list, check_var_has_name, "foo");
|
|
dispose_variable (elt);
|
|
*/
|
|
GENERIC_LIST *
|
|
delete_element (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
|