api/strncmp_8c_source.html

00001 /*
00002  * Copyright (C) 2004 by egnite Software GmbH. All rights reserved.
00003  *
00004  * Redistribution and use in source and binary forms, with or without
00005  * modification, are permitted provided that the following conditions
00006  * are met:
00007  *
00008  * 1. Redistributions of source code must retain the above copyright
00009  *    notice, this list of conditions and the following disclaimer.
00010  * 2. Redistributions in binary form must reproduce the above copyright
00011  *    notice, this list of conditions and the following disclaimer in the
00012  *    documentation and/or other materials provided with the distribution.
00013  * 3. Neither the name of the copyright holders nor the names of
00014  *    contributors may be used to endorse or promote products derived
00015  *    from this software without specific prior written permission.
00016  *
00017  * THIS SOFTWARE IS PROVIDED BY EGNITE SOFTWARE GMBH AND CONTRIBUTORS
00018  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
00019  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
00020  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL EGNITE
00021  * SOFTWARE GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
00022  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
00023  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
00024  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
00025  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
00026  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
00027  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
00028  * SUCH DAMAGE.
00029  *
00030  * For additional information see http://www.ethernut.de/
00031  *
00032  *-
00033  * Copyright (c) 1989 The Regents of the University of California.
00034  * All rights reserved.
00035  *
00036  * Redistribution and use in source and binary forms, with or without
00037  * modification, are permitted provided that the following conditions
00038  * are met:
00039  * 1. Redistributions of source code must retain the above copyright
00040  *    notice, this list of conditions and the following disclaimer.
00041  * 2. Redistributions in binary form must reproduce the above copyright
00042  *    notice, this list of conditions and the following disclaimer in the
00043  *    documentation and/or other materials provided with the distribution.
00044  * 3. Neither the name of the University nor the names of its contributors
00045  *    may be used to endorse or promote products derived from this software
00046  *    without specific prior written permission.
00047  *
00048  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
00049  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
00050  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
00051  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
00052  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
00053  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
00054  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
00055  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
00056  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
00057  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
00058  * SUCH DAMAGE.
00059  */
00060
00061 /*
00062  * $Log$
00063  * Revision 1.3  2008/02/15 17:13:16  haraldkipp
00064  * Use configurable constant attribute.
00065  *
00066  * Revision 1.2  2006/10/08 16:48:08  haraldkipp
00067  * Documentation fixed
00068  *
00069  * Revision 1.1  2004/09/08 10:24:10  haraldkipp
00070  * Generic C string library added
00071  *
00072  */
00073
00074 #include <compiler.h>
00075 #include <string.h>
00076
00081
00097 int strncmp(CONST char *s1, CONST char *s2, size_t n)
00098 {
00099
00100     if (n == 0)
00101         return (0);
00102     do {
00103         if (*s1 != *s2++)
00104             return (*(unsigned char *) s1 - *(unsigned char *) --s2);
00105         if (*s1++ == 0)
00106             break;
00107     } while (--n != 0);
00108     return (0);
00109 }
00110