Código: Seleccionar todo

unsigned long strlen(char* string)
{   //  By BlackZeroX ( http://Infrangelux.sytes.net/ )
    unsigned long i=0;
    while (*(string++) != '\0') i++;
    return i;
}

Código: Seleccionar todo

unsigned long instr(unsigned long start,char* string1,char* string2)
{
    unsigned long  q,c,limit;
    long ls2len;

    ls2len = strlen(string2) - 1;

    if ( ls2len >= 0 )
    {
        limit = strlen(string1)-ls2len;

        if ( limit > 1 )
        {
            q = start-1;
            while ( q < limit )
            {
                while ( string1[q+c] == string2[c] )
                {
                    c++;
                    if ( (c-1) == (unsigned long)ls2len )
                        return q+1;
                }
                q+=c+1;
                c=0;
            }
        }
    } else if (*string1 > '\0') {
        return 1;
    }
    return 0;
}

Código: Seleccionar todo

creando codigo..