Comment by ised | Hacker News Reader

Comment by ised | Hacker News Reader

OK, I am an intermediate to advanced BSD sed user. I can do things with only basic regex that I have seen others struggle to do with extended and Perl-compatible regex.

But I am as green as it gets when it comes to Javascript.

I am sometimes forced to use a Windows workstation.

So I installed "super sed" (ssed.exe), a Windows sed, from sed.sourceforge.net.

It is painfully slow. Ridiculously slow.

I'd like to try using Javascript to do some sed-style editing on text that comes through the browser.

Let's say I open up the Javascript console in a browser, e.g., Chrome.

I know little of Javascript but I do know about window.location() and XMLHttpRequest().

Assuming I can get the text I want to edit into the browser window... what do I do next?

If you have Chrome dev tools open, you can go to the console and define a variable that holds your text using an ES6 string template, like so:

   var text = `Hello World:
   Here is a multiline
   piece of text`

I would then follow this guide on JavaScript regex:

https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/R...

Here's a short example/sample, based on the text above: (You should be able to copy-paste this directly into the console as well, following the declaration of `text` above)

    // Logs the lines to console that match a certain regex.
    // This is a very poor approximation of grep.
    var re = /(Hello|text)/g

    text.split("\n").forEach(function(line) {
      if (line.match(re)) {
        console.log(line);
      }
    });

Using the JavaScript console of your browser is a great way to learn the language, prototype ideas and sometimes to debug into your webapp. (Sometimes it feels like hotswap when using the JVM :))

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