Saturday, September 24, 2011

转 C++结构体实例和类实例的初始化



struct S {  //class S 效果一样
    int            x;
    unsigned short y;
S testS1={100,123};
S testS2={200};//未指定的数据成初始化认值,os2.y=0;
S TestS[4]={ {100,10},
             {300} };//未指定的初始化认值,os[2].y,os[3].x,os[3].y


struct S { //class S可自行试验果相同
        int x;
        double y;
        S(int idemo,double ddemo) {x=idemo;y=ddemo;}
        void show(void) {cout<<x<<''/t''<<y<<endl;}
S os1;//构造函数(无参构造函数)
S os2(1000,2.345);
S os3=S(2000,4.567);
S os[4]={S(10,1.234),S(20,2.234)};//未初始化的将用默构造函数。如此没有默构造函数会出

        S os3=S(2000,4.567);句中,因是声明并初始化os3象,所以将S(int,double)构造函数os3行初始化。
        S os3(2000,4.567); 等价于 S os3=S(2000,4.567);
        但如果os3存在了,S os3(100,1.234);os3=S(2000,4.567)表示用一个临时对赋值给os3,将operator=,然后系临时产生的象。系=运算是将源象的数据成值复制到目标对象中的数据成中。


#include <iostream>
using namespace std;
class C {
        int x;
        C(int idemo) {x=idemo;}
        void show(void) {cout<<x<<endl;}
struct S {
        int x;
        S(int idemo) {x=idemo;}
        void show(void) {cout<<x<<endl;}
int main(int argc, char *argv[]){
    C oc=1000;//不能企加花括号;
    S os=2000;//不能企加花括号;
    return EXIT_SUCCESS;

Monday, September 12, 2011

apache2 php 安装

在ubuntu上安装apache2 和PHP5

如果是ubuntu 11.04 先装一下taskel

sudo apt-get install tasksel

sudo tasksel install lamp-server


sudo apt-get install apache2

sudo /etc/init.d/apache2 restart

如果出现了Could not determine the server's fully qualified domain name, using for ServerName 这种状况 那么

echo "ServerName localhost" | sudo tee /etc/apache2/conf.d/fqdn


Apache2 has the concept of sites, which are separate configuration files that Apache2 will read. These are available in/etc/apache2/sites-available. By default, there is one site available called default this is what you will see when you browse to http://localhost or You can have many different site configurations available, and activate only those that you need.
As an example, we want the default site to be /home/user/public_html/. To do this, we must create a new site and then enable it in Apache2.
To create a new site:
  • Copy the default website as a starting point. sudo cp /etc/apache2/sites-available/default /etc/apache2/sites-available/mysite 
  • Edit the new configuration file in a text editor "sudo nano" on the command line or "gksudo gedit", for example: gksudo gedit /etc/apache2/sites-available/mysite
  • Change the DocumentRoot to point to the new location. For example, /home/user/public_html/
  • Change the Directory directive, replace <Directory /var/www/> to <Directory /home/user/public_html/>
  • You can also set separate logs for each site. To do this, change the ErrorLog and CustomLog directives. This is optional, but handy if you have many sites
  • Save the file
Now, we must deactivate the old site, and activate our new one. Ubuntu provides two small utilities that take care of this: a2ensite (apache2enable site) and a2dissite (apache2disable site).
sudo a2dissite default && sudo a2ensite mysite

Finally, we restart Apache2:
sudo /etc/init.d/apache2 restart
If you have not created /home/user/public_html/, you will receive an warning message
To test the new site, create a file in /home/user/public_html/:
echo '<b>Hello! It is working!</b>' > /home/user/public_html/index.html
Finally, browse to http://localhost/

sudo apt-get install libapache2-mod-php5

sudo a2enmod php5

sudo service apache2 restart