How to Install Hyperledger Fabric 2.0 in Ubuntu 18.04

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Hyperledger Fabric is a consortium blockchain system. It’s performance is relatively good and its modular architecture enables it to be usable in many scenarios. Hyperledger Fabric itself has rich documents and samples of test networks. For beginners, deploying a new network for trying and testing still consumes quite some time. In this post, we will
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How to get file extension in JavaScript?

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How to get file extension from a file name in JavaScript? For examples, For “file.txt”, I want to get “txt”. For “file2.multi.ext.fileext”, I want to get “fileext”. This JavaScript function works well for me. function getExt(filename) { var idx = filename.lastIndexOf(‘.’); // handle cases like, .htaccess, filename return (idx < 1) ? “” : filename.substr(idx
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How to debug media print view of Web page in Firefox?

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How to debug the media print view set by @media print {} in CSS of Web pages in Firefox? In firefox, after opening the Web page, First, hit “Shift + F2” to open the “Developer Toolbar” at the bottom. Second, in the “Developer Toobar”, input media emulate print and Firefox will show the print view
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How to pass results from the opened window to the openning window in JavaScript?

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From the opening window by JavaScript window.open(), we can pass info to the opened by hash. But how to pass results back from the opened window to the openning window in JavaScript? Assume in the opener window, a JavaScript variable is defined like var exchangeVar = ”; In the opened window, you can update the
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How to capture the close event of an opened window by window.open() in JavaScript?

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How to capture the close event of an opened window by window.open() in JavaScript? This JavaScript code works well for me: var newwindow = window.open(“/newwindow.html”); newwindow.onbeforeunload = function () { // processing event here alert(“new window closed”); } Note that after the callback function is executed, the newwindow is closed.

How to open a URL in a new window in JavaScript?

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How to open a URL in a new window in JavaScript? For example, to open a new window to browse “http://www.systutorials.com“. Open the URL in a new window: url = “http://www.systutorials.com”; window.open(url); Some browser will open the window in a new tab depending on the configuration. If you want to force the browser to open
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How to exit the program in Node.js?

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When fatal error happened, we’d like to kill the program. How to exit the program in Node.js? You can use: process.exit() Here, “process” is a global process object. exit method ends the process. process.exit([code]) Ends the process with the specified code. If omitted, exit uses the ‘success’ code 0. To exit with a ‘failure’ code:
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How to make AdSense responsive ads show rectangle ads instead of horizontal ones?

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I noticed that many sites with AdSense responsive ads show large rectangle ads (336px x 280px) or large rectangle text ads (full width x 280px). However, in my own website (640px width content area), it shows most of time horizontal ones. How to make AdSense responsive ads show rectangle ads instead of horizontal ones? At
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How to redirect WordPress search query to Google CSE?

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How to redirect WordPress search query to Google CSE? You can configure Google CSE to read the query variable (by default, it is q). Then, in your WordPress’s .htaccess file, add these 2 lines RewriteCond %{QUERY_STRING} ^s=(.*)$ RewriteRule ^ https://www.google.com/cse/publicurl?cx=xyz&q=%1 [R,L] Here, “https://www.google.com/cse/publicurl?cx=xyz” is your CSE’s public URL or the webpage that contains the Google
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How to remove AdSense ads for mobile devices while keep them for desktops?

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I want to add adsense ads to be shown to visitors on desktop only. How to remove AdSense ads for mobile devices? You can achieve this through using “Responsive ad unit” of AdSense. The support article Create a responsive ad unit from AdSense discusses this and gives an example. Check the “Hiding an ad unit”
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How to download a rtmp stream on Linux?

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How to download a rtmp video stream on Linux? You can use mplayer to dump the rtmp stream like: mplayer -dumpstream rtmp://example.com/path/to/stream.mp4 It will generate ./stream.dump and you can rename it to the file with the extension you need like stream.mp4. The rtmp link usually can be found from the HTML or JavaScript source code
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Add my own window.onload safely without overwriting old ones

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My webpage has one existing window.onload javascript function defined by a javascript plugin in the <head> section. Now, I defined a new one and add it to the end of the HTML page: <script type=”text/javascript”> window.onload = function () { // great work here } </script> I find the new one overwrites the old one
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