I recently decided that I’d like to link to all of my blog posts from Twitter; obviously, this is a task for a script, and while I found a lot of blog posts describing one or two pieces of the process, when I put together a list of features I wanted:
- Periodically poll an XML Feed for blog posts
- In chronological order, link to new posts from Twitter
- Use an URL shortening/tracking service
- Automatically truncate long titles*
- Limit number of posts linked to per run
- No external dependencies (i.e., nonstandard PHP libraries, MySQL, etc)
and started Googling for it, all I came across were postings on various script-for-hire sites offering to buy or sell such a script, mostly in the $5-15 range. While that seems like a pretty small price to pay for the convenience, I don’t think I’d have been able to hold my head up high knowing that I’d paid someone else to write such a simple script. So, I started piecing together all of the parts, and came up with this PHP class, which I tossed up on Gist for public consumption:
As with many of my one-off scripts, this one is sorely lacking in documentation, and I’m not going to break it down line-by-line here as I often do, but I’ve intentionally broken down the steps into discrete chunks that should be pretty easy to digest. In general, the logical flow goes something like this:
- Load the timestamp of the last linked post from a file
- Load up the XML feed
- Starting at the end of the feed, loop through all entries
- Compare the date of each entry to the saved timestamp
- Shorten link to post using tr.im
- Calculate how much space we have left in the tweet for the title, and truncate if needed
- Post the title + link to Twitter
- Check if we’ve posted our max for this run
- Update the saved timestamp
The code linked above includes a sample invocation at the bottom, and can be called every other hour with a cron job entry similar to:
45 */2 * * * /export/scripts/TwitterFeedSync.php
I think it’s likely that the file I/O code, used to store and retrieve the timestamp of the most recent post, could be much more robust; in particular, you mught have to ‘touch’ the timestamp file into existence in order to get the script to run for the first time. Also, the default $date_format parameter is structured to work well with the feed for this blog, which of course is generated by Wordpress; other feeds may require some tweaking. But hopefully, someone out there besides myself can make use of this little snippet of code; if so, I’d encourage you to consider yourself $5-15 richer, and think about how you in turn can pass that value on to others in your world!
* as it turns out, I haven’t needed this yet; maybe I’ll pump up the length on this post’s title… 
