Re: [PATCH] queue.3: list: Complete example

["Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>]

On 10/15/20 1:29 PM, Alejandro Colomar wrote:
> Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>

Thanks, Alex. Patch applied.

Cheers,

Michael

> ---
>  man3/queue.3 | 105 +++++++++++++++++++++++++++------------------------
>  1 file changed, 55 insertions(+), 50 deletions(-)
> 
> diff --git a/man3/queue.3 b/man3/queue.3
> index fed8d126f..9cd6ff378 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>
> 


-- 
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/