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I am trying to make something which records my public ip address in a database, every few minutes.

I have already developed a web page which records the viewer's ip whenever loaded.

I would like to set up a cron job which will periodically load the page in the background. I know how to set up the cron job, but I don't know how to load a web page in the background from the command line.

How would you go about doing this?

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Presumably, the page was developed so that the user agent doesn’t actually have to be a browser. If this is the case, you can simply use the curl command to fetch the page.

If you’re running it as a cron job, you don’t want the command to print any output. To do this use, the --silent option for curl and discard the HTTP response by redirecting the output to /dev/null. E.g., add the following cron job to fetch the page every 10 minutes:

*/10 * * * * curl --silent http://example.com/path/to/page curl >/dev/null

If you want to be more efficient, you could develop your web page so that it responds to a HTTP HEAD request as well as GET requests. That way, you could use curl -I so only HTTP headers are sent between the server and the client.

  • If I'm not wrong, curl only fetches the page, not executes it. How would you write a page that executes when being fetched? – ginkoid Apr 12 '17 at 13:03
  • @Ginkoid curl doesn't "execute a page" while browsers only execute client-side code, e.g., JavaScript (they "interpret" HTML/CSS to render a page). Clients sends a HTTP request and the server responds to that request. For static content (such as images or HTML documents), it simply responds with the contents of a file. For dynamic content, the server executes some code and then responds with the results of that program(s). I figure you're most likely running some sort of server-side code (e.g., PHP) to record the IP address. It's probably worth editing your question to clarify how you do this. – Anthony Geoghegan Apr 12 '17 at 13:55
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  1. Select a programming language - Ruby, Python, Java or C#
  2. Write an instance of selenium webdriver, e.g. driver = Selenium::WebDriver.for :firefox
  3. Write the command to visit the URL, e.g. (Ruby) driver.get "http://www.google.com"
  4. Consider whether a direct GET would be better than using a browser

More info at http://www.seleniumhq.org/docs/03_webdriver.jsp#setting-up-a-selenium-webdriver-project

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