windows-nt-4.0/private/crt32/misc/lfind.c

/***
*lfind.c - do a linear search
*
*	Copyright (c) 1985-1991, Microsoft Corporation. All rights reserved.
*
*Purpose:
*	defines _lfind() - do a linear search of an array.
*
*Revision History:
*	06-19-85  TC	initial version
*	02-05-87  BM	changed <= to < in while condition to fix bug
*			of looking one element too far
*	12-11-87  JCR	Added "_LOAD_DS" to declaration
*	01-21-88  JCR	Backed out _LOAD_DS...
*	10-30-89  JCR	Added _cdecl to prototypes
*	03-14-90  GJF	Replaced _cdecl with _CALLTYPE1, added #include
*			<cruntime.h>, removed #include <register.h> and
*			fixed the copyright. Also, cleaned up the formatting
*			a bit.
*	04-05-90  GJF	Added #include <search.h> and fixed the resulting
*			compilation errors and warnings. Also, removed an
*			unreferenced local variable.
*	07-25-90  SBM	Replaced <stdio.h> by <stddef.h>
*	10-04-90  GJF	New-style function declarator.
*	01-17-91  GJF	ANSI naming.
*
*******************************************************************************/

#include <cruntime.h>
#include <search.h>
#include <stddef.h>

/***
*char *_lfind(key, base, num, width, compare) - do a linear search
*
*Purpose:
*	Performs a linear search on the array, looking for the value key
*	in an array of num elements of width bytes in size.  Returns
*	a pointer to the array value if found, NULL if not found.
*
*Entry:
*	char *key - key to search for
*	char *base - base of array to search
*	unsigned *num - number of elements in array
*	int width - number of bytes in each array element
*	int (*compare)() - pointer to function that compares two
*		array values, returning 0 if they are equal and non-0
*		if they are different.	Two pointers to array elements
*		are passed to this function.
*
*Exit:
*	if key found:
*		returns pointer to array element
*	if key not found:
*		returns NULL
*
*Exceptions:
*
*******************************************************************************/

void * _CALLTYPE1 _lfind (
	REG2 const void *key,
	REG1 const void *base,
	REG3 unsigned int *num,
	unsigned int width,
	int (_CALLTYPE1 *compare)(const void *, const void *)
	)
{
	unsigned int place = 0;
	while (place < *num )
		if (!(*compare)(key,base))
			return( (void *)base );
		else
		{
			base = (char *)base + width;
			place++;
		}
	return( NULL );
}