From: Alejandro Colomar <colomar.6.4.3@gmail.com>
Date: Thu, 15 Oct 2020 11:29:02 +0000 (+0200)
Subject: queue.3: list: Complete example
X-Git-Tag: man-pages-5.09~160
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7ef4fb8fcf828f1ecd214636814cfbe38cd6f05c;p=thirdparty%2Fman-pages.git

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>
---

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>