insque(3) -- Linux man page



insque, remque - insert/remove an item from a queue  


#include <search.h>

void insque(void *elem, void *prev);
void remque(void *elem);


insque() and remque() are functions for manipulating doubly-linked lists. Each element in the list is a structure of which the first two structure elements are a forward and a backward pointer.

insque() inserts the element pointed to by elem immediately after the element pointed to by prev, which must not be NULL.

remque() removes the element pointed to by elem from the doubly-linked list.  


POSIX 1003.1-2001  


Traditionally (e.g. SunOS, Linux libc 4,5) the parameters of these functions were of type struct qelem *, where the struct is defined as

struct qelem {
    struct    qelem *q_forw;
    struct    qelem *q_back;
    char      q_data[1];

This is still what you will get if _GNU_SOURCE is defined before including <search.h>.

The location of the prototypes for these functions differs among several versions of UNIX. The above is the POSIX version. Some systems place them in <string.h>. Linux libc4,5 placed them in <stdlib.h>.