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Diffstat (limited to 'libmisc/list.c')
| -rw-r--r-- | libmisc/list.c | 249 |
1 files changed, 249 insertions, 0 deletions
diff --git a/libmisc/list.c b/libmisc/list.c new file mode 100644 index 0000000..9d7ec77 --- /dev/null +++ b/libmisc/list.c @@ -0,0 +1,249 @@ +/* + * SPDX-FileCopyrightText: 1991 - 1994, Julianne Frances Haugh + * SPDX-FileCopyrightText: 1996 - 1997, Marek Michałkiewicz + * SPDX-FileCopyrightText: 2003 - 2005, Tomasz Kłoczko + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include <config.h> + +#ident "$Id$" + +#include <assert.h> +#include "prototypes.h" +#include "defines.h" +/* + * add_list - add a member to a list of group members + * + * the array of member names is searched for the new member + * name, and if not present it is added to a freshly allocated + * list of users. + */ +/*@only@*/ /*@out@*/char **add_list (/*@returned@*/ /*@only@*/char **list, const char *member) +{ + int i; + char **tmp; + + assert (NULL != member); + assert (NULL != list); + + /* + * Scan the list for the new name. Return the original list + * pointer if it is present. + */ + + for (i = 0; list[i] != (char *) 0; i++) { + if (strcmp (list[i], member) == 0) { + return list; + } + } + + /* + * Allocate a new list pointer large enough to hold all the + * old entries, and the new entries as well. + */ + + tmp = (char **) xmalloc ((i + 2) * sizeof member); + + /* + * Copy the original list to the new list, then append the + * new member and NULL terminate the result. This new list + * is returned to the invoker. + */ + + for (i = 0; list[i] != (char *) 0; i++) { + tmp[i] = list[i]; + } + + tmp[i] = xstrdup (member); + tmp[i+1] = (char *) 0; + + return tmp; +} + +/* + * del_list - delete a member from a list of group members + * + * the array of member names is searched for the old member + * name, and if present it is deleted from a freshly allocated + * list of users. + */ + +/*@only@*/ /*@out@*/char **del_list (/*@returned@*/ /*@only@*/char **list, const char *member) +{ + int i, j; + char **tmp; + + assert (NULL != member); + assert (NULL != list); + + /* + * Scan the list for the old name. Return the original list + * pointer if it is not present. + */ + + for (i = j = 0; list[i] != (char *) 0; i++) { + if (strcmp (list[i], member) != 0) { + j++; + } + } + + if (j == i) { + return list; + } + + /* + * Allocate a new list pointer large enough to hold all the + * old entries. + */ + + tmp = (char **) xmalloc ((j + 1) * sizeof member); + + /* + * Copy the original list except the deleted members to the + * new list, then NULL terminate the result. This new list + * is returned to the invoker. + */ + + for (i = j = 0; list[i] != (char *) 0; i++) { + if (strcmp (list[i], member) != 0) { + tmp[j] = list[i]; + j++; + } + } + + tmp[j] = (char *) 0; + + return tmp; +} + +/* + * Duplicate a list. + * The input list is not modified, but in order to allow the use of this + * function with list of members, the list elements are not enforced to be + * constant strings here. + */ +/*@only@*/ /*@out@*/char **dup_list (char *const *list) +{ + int i; + char **tmp; + + assert (NULL != list); + + for (i = 0; NULL != list[i]; i++); + + tmp = (char **) xmalloc ((i + 1) * sizeof (char *)); + + i = 0; + while (NULL != *list) { + tmp[i] = xstrdup (*list); + i++; + list++; + } + + tmp[i] = (char *) 0; + return tmp; +} + +/* + * Check if member is part of the input list + * The input list is not modified, but in order to allow the use of this + * function with list of members, the list elements are not enforced to be + * constant strings here. + */ +bool is_on_list (char *const *list, const char *member) +{ + assert (NULL != member); + assert (NULL != list); + + while (NULL != *list) { + if (strcmp (*list, member) == 0) { + return true; + } + list++; + } + + return false; +} + +/* + * comma_to_list - convert comma-separated list to (char *) array + */ + +/*@only@*/char **comma_to_list (const char *comma) +{ + char *members; + char **array; + int i; + char *cp; + char *cp2; + + assert (NULL != comma); + + /* + * Make a copy since we are going to be modifying the list + */ + + members = xstrdup (comma); + + /* + * Count the number of commas in the list + */ + + for (cp = members, i = 0;; i++) { + cp2 = strchr (cp, ','); + if (NULL != cp2) { + cp = cp2 + 1; + } else { + break; + } + } + + /* + * Add 2 - one for the ending NULL, the other for the last item + */ + + i += 2; + + /* + * Allocate the array we're going to store the pointers into. + */ + + array = (char **) xmalloc (sizeof (char *) * i); + + /* + * Empty list is special - 0 members, not 1 empty member. --marekm + */ + + if ('\0' == *members) { + *array = (char *) 0; + free (members); + return array; + } + + /* + * Now go walk that list all over again, this time building the + * array of pointers. + */ + + for (cp = members, i = 0;; i++) { + array[i] = cp; + cp2 = strchr (cp, ','); + if (NULL != cp2) { + *cp2 = '\0'; + cp2++; + cp = cp2; + } else { + array[i + 1] = (char *) 0; + break; + } + } + + /* + * Return the new array of pointers + */ + + return array; +} + |