NAME
lsearch - linear search and update

SYNOPSIS
#include <ccs/search.h>

char *lsearch ((char *)key, (char *)base, nelp, sizeof(*key), compar)
unsigned *nelp;
int (*compar)( );

DESCRIPTION
Lsearch is a linear search routine generalized from Knuth (6.1) Algorithm S. It returns a pointer into a table indicating where a datum may be found. If the datum does not occur, it is added at the end of the table. Key points to the datum 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 is incremented if the datum is added to the table. Compar is the name of the 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 zero if the elements are equal and non-zero otherwise.

NOTES
The pointers to the key and the element at the base of the table should be of type pointer-to-element, and cast to type pointer-to-character.
The comparison function need not compare every byte, so arbitrary data may be contained in the elements in addition to the values being compared.
Although declared as type pointer-to-character, the value returned should be cast into type pointer-to-element.

EXAMPLE
This fragment will read in less than TABSIZE strings of length less than ELSIZE and store them in a table, eliminating duplicates.

    #include <dmd.h>
    #include <dmdio.h>
    #include <ccs/search.h>
    #define TABSIZE 50
    #define ELSIZE 120
    	char line[ELSIZE], tab[TABSIZE][ELSIZE],
    			*lsearch( );
    	unsigned nel = 0;
    	int strcmp( );
    	. . .
    	while (fgets(line, ELSIZE, stdin) != NULL &&
    	   nel < TABSIZE)
    		(void) lsearch(line, (char *)tab, &nel,
    			  ELSIZE, strcmp);
    	. . .

SEE ALSO
bsearch(3L), str(3L).

DIAGNOSTICS
If the searched for datum is found, lsearch return a pointer to it. Otherwise, lsearch returns a pointer to the newly added element.

BUGS
Undefined results can occur if there is not enough room in the table to add a new item.