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| author | Alejandro Colomar <colomar.6.4.3@gmail.com> | 2020-10-15 13:29:02 +0200 |
|---|---|---|
| committer | Michael Kerrisk <mtk.manpages@gmail.com> | 2020-10-15 20:49:50 +0200 |
| commit | 7ef4fb8fcf828f1ecd214636814cfbe38cd6f05c (patch) | |
| tree | b8ba8b517c6429d65e2cd83748793c801c4fccab /man3/queue.3 | |
| parent | 4b6e3782e163bcc05ca2464647ce990af079feb7 (diff) | |
| download | man-pages-7ef4fb8fcf828f1ecd214636814cfbe38cd6f05c.tar.gz | |
queue.3: list: Complete example
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Diffstat (limited to 'man3/queue.3')
| -rw-r--r-- | man3/queue.3 | 105 |
1 files changed, 55 insertions, 50 deletions
diff --git a/man3/queue.3 b/man3/queue.3 index fed8d126f5..9cd6ff378a 100644 --- a/man3/queue.3 +++ b/man3/queue.3 @@ -921,56 +921,8 @@ from the list. .\" .Fa head1 .\" and .\" .Fa head2 . -.Ss List example -.Bd -literal -LIST_HEAD(listhead, entry) head = - LIST_HEAD_INITIALIZER(head); -struct listhead *headp; /* List head. */ -struct entry { - ... - LIST_ENTRY(entry) entries; /* List. */ - ... -} *n1, *n2, *n3, *np, *np_temp; - -LIST_INIT(&head); /* Initialize the list. */ - -n1 = malloc(sizeof(struct entry)); /* Insert at the head. */ -LIST_INSERT_HEAD(&head, n1, entries); - -n2 = malloc(sizeof(struct entry)); /* Insert after. */ -LIST_INSERT_AFTER(n1, n2, entries); - -n3 = malloc(sizeof(struct entry)); /* Insert before. */ -LIST_INSERT_BEFORE(n2, n3, entries); - -LIST_REMOVE(n2, entries); /* Deletion. */ -free(n2); - /* Forward traversal. */ -LIST_FOREACH(np, &head, entries) - np\-> ... - -.\" /* Safe forward traversal. */ -.\" LIST_FOREACH_SAFE(np, &head, entries, np_temp) { -.\" np\->do_stuff(); -.\" ... -.\" LIST_REMOVE(np, entries); -.\" free(np); -.\" } -.\" -while (!LIST_EMPTY(&head)) { /* List Deletion. */ - n1 = LIST_FIRST(&head); - LIST_REMOVE(n1, entries); - free(n1); -} - -n1 = LIST_FIRST(&head); /* Faster List Deletion. */ -while (n1 != NULL) { - n2 = LIST_NEXT(n1, entries); - free(n1); - n1 = n2; -} -LIST_INIT(&head); -.Ed +.Pp +See the EXAMPLES section below for an example program using a linked list. .Ss Tail queues A tail queue is headed by a structure defined by the .Nm TAILQ_HEAD @@ -1376,6 +1328,59 @@ main(void) exit(EXIT_SUCCESS); } .Ed +.Ss List example +.Bd -literal +#include <stddef.h> +#include <stdio.h> +#include <stdlib.h> +#include <sys/queue.h> + +struct entry { + int data; + LIST_ENTRY(entry) entries; /* List. */ +}; + +LIST_HEAD(listhead, entry); + +int +main(void) +{ + struct entry *n1, *n2, *n3, *np; + struct listhead head; /* List head. */ + int i; + + LIST_INIT(&head); /* Initialize the list. */ + + n1 = malloc(sizeof(struct entry)); /* Insert at the head. */ + LIST_INSERT_HEAD(&head, n1, entries); + + n2 = malloc(sizeof(struct entry)); /* Insert after. */ + LIST_INSERT_AFTER(n1, n2, entries); + + n3 = malloc(sizeof(struct entry)); /* Insert before. */ + LIST_INSERT_BEFORE(n2, n3, entries); + + i = 0; /* Forward traversal. */ + LIST_FOREACH(np, &head, entries) + np->data = i++; + + LIST_REMOVE(n2, entries); /* Deletion. */ + free(n2); + /* Forward traversal. */ + LIST_FOREACH(np, &head, entries) + printf("%i\en", np->data); + /* List Deletion. */ + n1 = LIST_FIRST(&head); + while (n1 != NULL) { + n2 = LIST_NEXT(n1, entries); + free(n1); + n1 = n2; + } + LIST_INIT(&head); + + exit(EXIT_SUCCESS); +} +.Ed .Ss Tail queue example .Bd -literal #include <stddef.h> |