hsearch() -- search hash table

SYNOPSIS

#include <search.h>

ENTRY *hsearch(ENTRY item, ACTION action);

The hsearch() function is a hash-table search routine. It returns a pointer into a hash table indicating the location where an entry can be found. The comparison function used by hsearch() is strcmp().

PARAMETERS

item

Is a structure containing two pointers:

key: Points to the comparison key.
data: Points to any data associated with that key.

action

Either ENTER or FIND. When ENTER is specified, the item is inserted in the table at an appropriate point; an existing item with the same key is not overwritten. When FIND is specified, the item is not inserted into the table. When an entry exists with the specified key, it is returned, otherwise NULL is returned.

RETURN VALUES

The hsearch() function returns a null pointer if either the action is FIND and the item could not be found, or the action is ENTER and the table is full. Otherwise, a pointer to the entry matching the specified key is returned.