💾 Archived View for zaibatsu.circumlunar.space › ~solderpunk › phlog › introducing-vf1.txt captured on 2020-09-24 at 01:51:32.
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Introducting VF-1 ----------------- Well, as threatened I have written a basic Gopher client. This post is an introduction and brief tutorial for those who want to play around with it, offer feedback, hunt oug bugs (which surely exist, etc). Firstly, I've called the client "VF-1", after the VF-1 Valkyrie aircraft in the Macross anime. This is, of course, a nod to SDF and the role it has played in keeping Gopher alive (for the unaware, SDF was originally a bulletin board for anime fans to discuss Macross). I fully acknowledge that this is an awkward name. I originally intended it only as a working name until I thought of something better, but it's grown on me. VF-1 is written in Python, specifically in Python 3. All of the "gopher stuff" is done using code I lifted from the old "gopherlib" module which used to be part of the Python standard library until it was removed in Python 2.5. I have made the bare minimum of changes to the original library's code, basically just done what I had to do to make it play nicely with Python 3 and unicode. Everything is done using the standard library, there are no dependencies. Right now it is in one file. You can find it in my Gopherhole if you go to the "Misc files" section from the front page. If you are a SDF user, it is also in my home directory with globally readable permissions. There is no hashbang magic at the start of the file, so invoke it using e.g. "python3 ~/vf1.py" or, on SDF, "python3.6 ~/vf1.py". If you want to use it on SDF, you will first need to set the environment variable PYTHONIOENCODING="UTF-8". I think this has something to do with local settings on SDF. I did not need to do this on my Debian machine which I developed the client on. Assuming you have been able to run it, you should now be staring at a "VF-1>" prompt. Yep, VF-1 is built around an interactive command prompt, and has a very "REPL" feeling. You only need a small number of commands to get around, and most of them can be abbreviated to one or two chars, so with practice you can get around very quickly. You can safely unplug your mouse the entire time you are using VF-1. :) Well, let's start off by heading to SDF to check out some nice phlogs! Use the "go" command: VF-1> go sdf.org/ (don't leave off the trailing slash - this won't be necessary in future releases, but right now it is required for technical reasons I won't get into) (if you are very lazy, you can type "g sdf.org/" instead, i.e. you can abbreviate "go" to "g") You should see a listing of the SDF Gopherspace. The different menu items are indicated by numbers in square brackets, and the SDF Member PHLOGOSPHERE is option [1], so go ahead and type "1" and then enter: VF-1> 1 You should see all the phlogs fly by, and unless you have a very large monitor some have probably run off the top of the screen. This will not be an uncommon problem, and there are various ways to deal with it. Obviously, you can scroll up in your terminal like always, but VF-1 gives you other ways to deal with this. After you have visited a gopher menu (as opposed to a document), if you just press Enter (i.e. execute an empty line), VF-1 will print the first 10 items in the menu by themselves (any ASCII art etc. in the original listing is removed in this mode). Each time you press enter you will see the next ten items in the listing. Page through a few times to get a feel for it. If you just want to see which phlogs have been updated lately, that's probably enough for you. But suppose you are really curious about one phlog in particular. Say you want to know what Tomasino has been up to. You could search for his phlog specifically: VF-1> search tom (if you are very lazy, you can use "/" instead of "search", i.e. "/ tom") This will show you the phlogs with "tom" in them (it's a simple case-insensitive search). Tomasino will probably be [1] or [2] (depends whether tomatobodhi has updated more recently :). So go ahead and type "1" and hit enter again to enter Tomasino's gopherhole. Then you can type "2" and enter to go to his phlog, and then "1" and enter to read his most recent entry about Kindles. Suppose now you want to go back to the main SDF phlog listing. Let's check out your history: VF-1> history (if you are very lazy, you can abbreviate "history" to "hist", and in fact if you are fiendishly lazy you can just use "h") You should this time see a menu of the few places you've been so far. The phlogosphere list will probably be [2], so type "2" and enter to go back there. By now you are probably getting the hang of using numbers to get around. For this next bit, let's focus on gunnarfrost's phlog, because he writes very nice short entries which work well for this. Once you're at the main phlog listing, do a: VF-1> search frost To easily find gunnarfrost's phlog and then press [1] to type the first entry. Short and sweet! Now, suppose you want to read his next post. You *could* use the "back" command to go back to the menu listing and then press "2", and then do "back" and "3", "back" and "4", etc. But it's much easier to just type: VF-1> next (or, if you are lazy, just "n") This will automatically take you to the next item in the most recently seen gopher menu after the one you just viewed. So you can just hit "n" and enter again and again to flip through the pages of gunnar's phlog. Each one is much shorter than a full screen, so this works very nicely. Lately gunnarfrost is a good phlogger and wraps his entries at 70 or 80 chars or thereabouts. But if you keep hitting "n" you'll get to early entries where the lines just keep going until your terminal wraps them (sorry, gunnarfrost, I don't mean to single you out here, plenty of other folk do this too!). Once you've found one of these, try running: VF-1> fold And VF-1 will wrap the lines at 80 chars for you (assuming you have the "fold" command installed on whatever system you are using). This isn't the only helper command of this kind available. Get back to the main SDF phlog listing (either by running "back" a few times or using "hist" and a number to jump straight to it) and go to my phlog. Unlike gunnarfrost, I appear to be physiologically incapable of writing phlog posts which are less than a few whole screens long. Go to one of these posts (say my most recent "assorted replies and acknowledgements"), and watch the lines fly by. Now try: VF-1> less This will pipe my giant entry through "less", so you can move back and forth and read it. Just press "q" when you're done like usual to get your VF-1 prompt back. I have quite a few references at the end of that entry. You might be tempted to pick up your mouse, highlight those urls, and use the "go" command to visit them. Put that rodent down! The mouse, that is, not the gopher. Instead, try this command: VF-1> links VF-1 will then scan the most recently viewed post for URLs. Well, actually, it scans for words (i.e. things separated by spaces) which contain "://" and at least one ".". This might not catch all URLs and it might sometimes catch things which are not URLs, but it works well enough for now. You will see a menu and now you can use numbers to follow any of those links without your mouse! If you want to know the URL of a document you are at so that you can refer to it, just do: VF-1> url If you want to save the document, just do: VF-1> save ~/some/random/path/somefilename.txt Everything so far has been text-based. Gopher items with itemtype 0 (text) are fed to the "cat" command by default, or to "less" or "fold" if you request it. But VF-1 can handle other itemtypes too. Image files with an item type of "g" or "I" will be opened using the "feh" image viewer (if installed). HTML content with an item type of "h" will be fed to "lynx --dump", and audio files with an item type of "a" will be fed to "mpg123" (e.g. you can listen to jynx's doom metal songs in this way). Obviously if you do not have one of these programs installed, it will not work. In future I may provide some nice way to customise which 3rd party programs are used for different item types. For now, if you want to use different programs, you will have to edit the code. It's not hard, just look for the _HANDLERS dictionary near the top of vf1.py and change accordingly. This pretty much covers the basics! I hope to add a bookmarking function soon. In the meantime, I have hardcoded two commands in there. You can always type "sdf" to jump to sdf.org, and you can always type "bongusa" to go to Bongusta. To make a few implcit concepts explicit: