queue.3: stailq: 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 9cd6ff378aa95dfb4907f908ebbaff1423f99f58..c48b4ba9f417b479f9d5b4a710f9f35e91a90616 100644 (file)
--- a/man3/queue.3
+++ b/man3/queue.3
@@ -721,59 +721,9 @@ from the tail queue.
 .\" .Fa head1
 .\" and
 .\" .Fa head2 .
-.Ss Singly-linked tail queue example
-.Bd -literal
-STAILQ_HEAD(stailhead, entry) head =
-    STAILQ_HEAD_INITIALIZER(head);
-struct stailhead *headp;               /* Singly-linked tail queue head. */
-struct entry {
-       ...
-       STAILQ_ENTRY(entry) entries;    /* Tail queue. */
-       ...
-} *n1, *n2, *n3, *np;
-
-STAILQ_INIT(&head);                    /* Initialize the queue. */
-
-n1 = malloc(sizeof(struct entry));     /* Insert at the head. */
-STAILQ_INSERT_HEAD(&head, n1, entries);
-
-n1 = malloc(sizeof(struct entry));     /* Insert at the tail. */
-STAILQ_INSERT_TAIL(&head, n1, entries);
-
-n2 = malloc(sizeof(struct entry));     /* Insert after. */
-STAILQ_INSERT_AFTER(&head, n1, n2, entries);
-                                       /* Deletion. */
-STAILQ_REMOVE(&head, n2, entry, entries);
-free(n2);
-                                       /* Deletion from the head. */
-n3 = STAILQ_FIRST(&head);
-STAILQ_REMOVE_HEAD(&head, entries);
-free(n3);
-                                       /* Forward traversal. */
-STAILQ_FOREACH(np, &head, entries)
-       np\-> ...
-.\"                                    /* Safe forward traversal. */
-.\"STAILQ_FOREACH_SAFE(np, &head, entries, np_temp) {
-.\"    np\->do_stuff();
-.\"    ...
-.\"    STAILQ_REMOVE(&head, np, entry, entries);
-.\"    free(np);
-.\"}
-                                       /* TailQ Deletion. */
-while (!STAILQ_EMPTY(&head)) {
-       n1 = STAILQ_FIRST(&head);
-       STAILQ_REMOVE_HEAD(&head, entries);
-       free(n1);
-}
-                                       /* Faster TailQ Deletion. */
-n1 = STAILQ_FIRST(&head);
-while (n1 != NULL) {
-       n2 = STAILQ_NEXT(n1, entries);
-       free(n1);
-       n1 = n2;
-}
-STAILQ_INIT(&head);
-.Ed
+.Pp
+See the EXAMPLES section below for an example program
+using a singly-linked tail queue.
 .Ss Lists
 A list is headed by a structure defined by the
 .Nm LIST_HEAD
@@ -1328,6 +1278,67 @@ main(void)
     exit(EXIT_SUCCESS);
 }
 .Ed
+.Ss Singly-linked tail queue example
+.Bd -literal
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/queue.h>
+
+struct entry {
+    int data;
+    STAILQ_ENTRY(entry) entries;            /* Singly-linked tail queue. */
+};
+
+STAILQ_HEAD(stailhead, entry);
+
+int
+main(void)
+{
+    struct entry    *n1, *n2, *n3, *np;
+    struct stailhead head;                  /* Singly-linked tail queue
+                                               head. */
+
+    STAILQ_INIT(&head);                     /* Initialize the queue. */
+
+    n1 = malloc(sizeof(struct entry));      /* Insert at the head. */
+    STAILQ_INSERT_HEAD(&head, n1, entries);
+
+    n1 = malloc(sizeof(struct entry));      /* Insert at the tail. */
+    STAILQ_INSERT_TAIL(&head, n1, entries);
+
+    n2 = malloc(sizeof(struct entry));      /* Insert after. */
+    STAILQ_INSERT_AFTER(&head, n1, n2, entries);
+
+    STAILQ_REMOVE(&head, n2, entry, entries);/* Deletion. */
+    free(n2);
+
+    n3 = STAILQ_FIRST(&head);
+    STAILQ_REMOVE_HEAD(&head, entries);     /* Deletion from the head. */
+    free(n3);
+
+    n1 = STAILQ_FIRST(&head);
+    n1->data = 0;
+    for (int i = 1; i < 5; i++) {
+        n1 = malloc(sizeof(struct entry));
+        STAILQ_INSERT_HEAD(&head, n1, entries);
+        n1->data = i;
+    }
+                                            /* Forward traversal. */
+    STAILQ_FOREACH(np, &head, entries)
+        printf("%i\en", np->data);
+                                            /* TailQ Deletion. */
+    n1 = STAILQ_FIRST(&head);
+    while (n1 != NULL) {
+        n2 = STAILQ_NEXT(n1, entries);
+        free(n1);
+        n1 = n2;
+    }
+    STAILQ_INIT(&head);
+
+    exit(EXIT_SUCCESS);
+}
+.Ed
 .Ss List example
 .Bd -literal
 #include <stddef.h>