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3.2.34 dll_utraverse

Traverse a doubly linked list either forwards or backwards, processing each node.

Synopsis

     #include <linklist/linklist.h>
     
     
     
int dll_utraverse( DLinkList ull, int (*action)(void *node,void *udata), void *udata, LinkTraverseDirection direction );

Parameters

DLinkList ull
A handle to the list to traverse
int (*action)(void *node,void *udata)
The user supplied action routine applied to each node
void *udata
a pointer to data to be passed to the action routine
LinkTraverseDirection direction
the direction in which to traverse the list
          
          
Possible values for a LinkTraverseDirection are as follows: HEAD_TO_TAIL, TAIL_TO_HEAD

Description

This routine walks along a list, calling a user supplied action function at each node. The action routine is passed the node's data pointer as well as a pointer provided by the calling routine, thus allowing arbitrary data to be available to the action routine. If an invocation of the action routine returns non-zero the traversal is aborted and the action routine's return value is returned.

Compare this to dll_traverse, dll_traverse_d, and dll_utraverse_d.

Returns

If the action routines all return ‘0’, it returns ‘0’, else it returns the value returned by the last action routine called.