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 fed8d126f52072c9539562b0f90d3859d1c29cb7..9cd6ff378aa95dfb4907f908ebbaff1423f99f58 100644 (file)
--- 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>