genericopenlibs/cstdlib/LCHAR/STRNCMP.C
changeset 0 e4d67989cc36
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/genericopenlibs/cstdlib/LCHAR/STRNCMP.C	Tue Feb 02 02:01:42 2010 +0200
@@ -0,0 +1,80 @@
+/*
+* Copyright (c) 1997-2009 Nokia Corporation and/or its subsidiary(-ies).
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of "Eclipse Public License v1.0"
+* which accompanies this distribution, and is available
+* at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*
+* Initial Contributors:
+* Nokia Corporation - initial contribution.
+*
+* Contributors:
+*
+* Description:
+* FUNCTION
+* <<strncmp>>---character string compare
+* INDEX
+* strncmp
+* ANSI_SYNOPSIS
+* #include <string.h>
+* int strncmp(const char *<[a]>, const char * <[b]>, size_t <[length]>);
+* TRAD_SYNOPSIS
+* #include <string.h>
+* int strncmp(<[a]>, <[b]>, <[length]>)
+* char *<[a]>;
+* char *<[b]>;
+* size_t <[length]>
+* <<strncmp>> compares up to <[length]> characters
+* from the string at <[a]> to the string at <[b]>.
+* RETURNS
+* If <<*<[a]>>> sorts lexicographically after <<*<[b]>>>,
+* <<strncmp>> returns a number greater than zero.  If the two
+* strings are equivalent, <<strncmp>> returns zero.  If <<*<[a]>>>
+* sorts lexicographically before <<*<[b]>>>, <<strncmp>> returns a
+* number less than zero.
+* PORTABILITY
+* <<strncmp>> is ANSI C.
+* <<strncmp>> requires no supporting OS subroutines.
+* QUICKREF
+* strncmp ansi pure
+* 
+*
+*/
+
+
+
+#include <string.h>
+
+/**
+Compare some characters of two strings.
+Compares the first num characters of string1 to the first num characters of string2.
+The comparison is performed character by character. 
+If a character that is not equal in both strings is found the function ends 
+and returns a value that determines which of them was greater.
+@return a value indicating the lexicographical relation between the strings.
+@param s1 Null-terminated string to compare 
+@param s2 Null-terminated string to compare. 
+@param n Maximum number of characters to compare.
+*/
+EXPORT_C int 
+strncmp (const char *s1, const char *s2, size_t n)
+{
+	const unsigned char* p1 = (const unsigned char*)s1;
+	const unsigned char* p2 = (const unsigned char*)s2;
+
+	if (n == 0)
+		return 0;
+
+	for (;;)
+	{
+		int c1 = *p1++;
+		int d = c1 - *p2++;
+		if (d != 0)
+			return d;
+		if (c1 == 0)
+			return d;
+		if (--n == 0)
+			return d;
+	}
+}