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.\" ========================================================================
.\"
.IX Title "libinn_list 3"
.TH libinn_list 3 2024-04-01 "INN 2.7.2" "InterNetNews Documentation"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
.\" way too many mistakes in technical documents.
.if n .ad l
.nh
.SH NAME
list \- list routines
.SH SYNOPSIS
.IX Header "SYNOPSIS"
.Vb 1
\&    #include <inn/list.h>
\&
\&    struct node {
\&        struct node *succ;
\&        struct node *pred;
\&    };
\&
\&    struct list {
\&        struct node *head;
\&        struct node *tail;
\&        struct node *tailpred;
\&    };
\&
\&    void list_new(struct list *list);
\&
\&    struct node *list_addhead(struct list *list, struct node *node);
\&
\&    struct node *list_addtail(struct list *list, struct node *node);
\&
\&    struct node *list_head(struct list *list);
\&
\&    struct node *list_tail(struct list *list);
\&
\&    struct node *list_succ(struct node *node);
\&
\&    struct node *list_pred(struct node *node);
\&
\&    struct node *list_remhead(struct list *list);
\&
\&    struct node *list_remtail(struct list *list);
\&
\&    struct node *list_remove(struct node *node);
\&
\&    struct node *list_insert(struct list *list, struct node *node,
\&                             struct node *pred);
\&
\&    bool list_isempty(struct list *list);
.Ve
.SH DESCRIPTION
.IX Header "DESCRIPTION"
\&\fBlist_new\fR initialises the list header \fIlist\fR so as to create an
empty list.
.PP
\&\fBlist_addhead\fR adds \fInode\fR to the head of \fIlist\fR, returning the node
just added.
.PP
\&\fBlist_addtail\fR adds \fInode\fR to the tail of \fIlist\fR, returning the node
just added.
.PP
\&\fBlist_head\fR returns a pointer to the node at the head of \fIlist\fR
or \fBNULL\fR if the list is empty.
.PP
\&\fBlist_tail\fR returns a pointer to the node at the tail of \fIlist\fR
or \fBNULL\fR if the list is empty.
.PP
\&\fBlist_succ\fR returns the next (successor) node on the list after
\&\fInode\fR or \fBNULL\fR if \fInode\fR was the final node.
.PP
\&\fBlist_pred\fR returns the previous (predecessor) node on the list before
\&\fInode\fR or \fBNULL\fR if \fInode\fR was the first node.
.PP
\&\fBlist_remhead\fR removes the first node from \fIlist\fR and returns it to
the caller.  If the list is empty \fBNULL\fR is returned.
.PP
\&\fBlist_remtail\fR removes the last node from \fIlist\fR and returns it to
the caller.  If the list is empty \fBNULL\fR is returned.
.PP
\&\fBlist_remove\fR removes \fInode\fR from the list it is on and returns it
to the caller.
.PP
\&\fBlist_insert\fR inserts \fInode\fR onto \fIlist\fR after the node \fIpred\fR.  If
\&\fIpred\fR is \fBNULL\fR then \fInode\fR is added to the head of \fIlist\fR.
.SH HISTORY
.IX Header "HISTORY"
Written by Alex Kiernan <alex.kiernan@thus.net> for InterNetNews\ 2.4.0.