lsearch, lfind - linear search and update

Syntax

#include <search.h> void *lsearch (const void *key, void * base, size_t *nelp, size_t width, int ( *compar) (const void *, const void *)); void *lfind (const void *key, const void *base, size_t *nelp, size_t width, int ( *compar)(const void *, const void *));

Description lsearch() is a linear search routine. It returns a pointer into a table indicating the position

	at which a specific value may be found. If the searched value is not present, it is added at the end of the table. key points to the entry to be sought in the table; base points to the first element in the table; nelp points to an integer containing the current number of elements in the table. The integer to which nelp points is incremented if the entry is added to the table. width is the size of an element in bytes. compar points to a comparison function which the user must supply (strcmp(), for example). It is called with two arguments that point to the elements being compared. The function must return 0 if the elements are equal and non-zero otherwise. lfind() has the same effect as lsearch() except that if the entry is not found, it is not added to the table. Instead, a null pointer is returned.
Return val.	*key	lfind(): if successful. lsearch(): if successful, and also for a newly added element.
	Null pointer	lfind(): if an error occurs.
Notes	The comparison function need not compare every byte, so arbitrary data may be contained in the elements in addition to the values being compared. Undefined results can occur if there is not enough room in the table to add a new item. Extension The pointers to the key and the element at the base of the table may be pointers of any type. The returned value should be convertible to the type pointer to element. (End)
See also	bsearch(), hsearch(), tsearch(), search.h.