windows-nt/Source/XPSP1/NT/base/crts/crtw32/misc/lfind.c

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2020-09-26 03:20:57 -05:00
/***
*lfind.c - do a linear search
*
* Copyright (c) 1985-2001, 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.
* 04-06-93 SKS Replace _CRTAPI* with __cdecl
*
*******************************************************************************/
#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 * __cdecl _lfind (
REG2 const void *key,
REG1 const void *base,
REG3 unsigned int *num,
unsigned int width,
int (__cdecl *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 );
}