[英]Check if a file exists, if not create one, Javascript
I know this question have already been asked. 我知道这个问题已经被问到了。 BUT NONE of this , this , this , this , this or this solutions worked for me.
但没有这个 , 这个 , 这个 , 这个 , 这个和这个解决方案为我工作。 I'm only using HTML / CSS / JS for the moment on my website.
我目前仅在网站上使用HTML / CSS / JS。 Later this should run on an apache or IIS server.
稍后,它应在apache或IIS服务器上运行。
Situation : On my website I wish user to access different servers. 情况:在我的网站上,我希望用户访问其他服务器。 I got a html select with a lot of choice.
我有很多选择的HTML选择。 Once they made their choice and click on connection button I check the choice they made and open it (it's a web interface like 127.0.0.1) in a new tab the link.
他们做出选择并单击“连接”按钮后,我会检查他们做出的选择,然后在新标签页的链接中打开它(如127.0.0.1这样的Web界面)。
Problem : Some of the servers should not being accesssed if one is already used. 问题:如果某些服务器已经使用过,则不应对其进行访问。 Example : If 127.0.0.1 is used by someone, no one should access 128.0.0.1 or 129.0.0.1
示例:如果某人使用了127.0.0.1,则任何人都不应访问128.0.0.1或129.0.0.1
The solution I found was creating a file when someone access 127.0.0.1. 我发现的解决方案是当有人访问127.0.0.1时创建文件。 So when someone want to access 128.0.0.1 or 129.0.0.1, I check if the file exists.
因此,当有人要访问128.0.0.1或129.0.0.1时,我检查文件是否存在。 If it does exists I don't open the link and show an alert, if it does not exist I create it and open the link in new tab.
如果确实存在,则不打开链接并显示警报;如果不存在,则创建并在新选项卡中打开链接。
Another problem : How can I know when the tab will be closed in order to delete the file ? 另一个问题:如何知道何时关闭标签页才能删除文件? Have you got another solution to this problem ?
您有解决此问题的另一种方法吗?
Thx in advance for helping me, I'm just a beginner in web. 事先感谢您的帮助,我只是Web的初学者。 No solutions worked for me so far ...
到目前为止,没有解决方案对我有用...
This code help you to detect when user close a tab. 此代码可帮助您检测用户何时关闭选项卡。
<script>
window.onbeforeunload = function () {
//write your code here
return false;
};
<script>
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