内存查找函数

简单的内存查找.

/***************************************************************
* name     : xmemsearch                                        *
* parameter: target\search                                     *
*      tlen: the length of target string                       *
*      slen: the length of search string                       *
* developer: [e-mail]                             *
* date     : 2008-01-19                                        *
***************************************************************/
const unsigned char *xmemsearch( const unsigned char *target, size_t tlen, const unsigned char *search, size_t slen)
{
    const unsigned char *p = NULL;
    unsigned long i = 0;

    for( p = target; p <= target + tlen - slen; p++) {

        if( *p == search[0]) {

            for( i = 0; i < slen && p < target + tlen && *p == search[i]; i++, p++) {

                if( i == (slen-1)) {
                    return p - (slen-1);
                }
            }
        }
    }

    return NULL;
}

int main( int argc, char *argv[])
{
    unsigned char t[] = "abcdefbcda\0abb\0n";
    unsigned char s[] = "abb";

    const unsigned char *p = xmemsearch( t, sizeof(t)-1, s, sizeof(s)-1);

    printf("target len:%03d target:[%s]\n", sizeof(t)-1, t);
    printf("search len:%03d search:[%s]\n", sizeof(s)-1, s);
    printf("found:[%s]\n", p);

    return 0;
}