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Comment by brian_herman__ | Hacker News Reader

I tried out SDF when I wanted to give someone some basic intros to how to use the shell and do shell scripting, and was looking around for something that provided some kind of free shell access.

The problem is, unless you donate or find someone to sponsor you, you don't actually get shell access; you get some very limited BBS functionality. And even once you do donate to get the basic access level, there are a number of basic programs (like Python and a C compiler) that aren't executable without getting a higher access level.

I wound up installing my own local version of pkgsrc in my home directory just to see if I could use that work around the issue, but that's not really a good option for the "teach someone how to use a Unix shell" use case.

It's easier to just spin up a free tier VM on one of the cloud providers than it is to use the "Public Access Unix" on SDF.

The SDF system was created at a time (1987) when accessing to a timesharing Unix system was a rarity for the majority of PC users who's outside of an institution, thus "Public Access Unix System".

At that time, the creation of a public minicomputer running Unix, which you can telnet into was groundbreaking. And in the late 90s when the WWW was taking off, it offered a wide ranges of community services, including a shell, access to newsgroups, Gopher, E-mail, IRC, and being an ISP with dial-up and DSL network connection, that served as a great platform to your online presence.

The time has changed and today it doesn't have the significance that it was. Running a system by yourself or renting a virtual server makes more sense.

Although SDF itself is still a good community, and now has a Minecraft server and a Mastodon server in addition to the technical BBS.

Definitely agree on just spinning up a free tier VM for very mild use cases or for a jump box or testing, or for troubleshooting network/provider/access issues. Google's always(?)-free tier 600M F1 Micro instance works nicely for this. Be aware only 1G transfer in the free tier though.

> The problem is, unless you donate or find someone to sponsor you, you don't actually get shell access; you get some very limited BBS functionality. And even once you do donate to get the basic access level, there are a number of basic programs (like Python and a C compiler) that aren't executable without getting a higher access level.

Eh? It takes a minute of dropping in on com to get someone to verify you, and after that you have access to everything in the 'basic' user level -- which does indeed give you access to compilers and the like.

SDF appears to be down right now (maybe too much attention from this thread?), but according to the archive https://web.archive.org/web/20180503065444/http://sdf.org:80..., you need the ARPA membership level ($36) for "outbound telnet, ssh, sftp, ftp, ytalk, irc, snarf, wget" and "gcc, elisp, perl, php, python, ruby", and this matches what I recall from when I tried.

There are the "instructor" and "student" levels, but since this wasn't an official course I was running but just "I want to show someone the ropes of Bash scripting," I found it a lot easier to just spin up a free-tier VM on Google than try to find someone who could give me the appropriate membership level.

It's back up again, and I checked. Right now gcc and some versions of Python are usable for people in the "users" group, but others are not:

  lrwxr-xr-x  1 root  wheel     9 Jan  2  2018 /usr/pkg/bin/python -> python2.7
  -rwx---r-x  1 root  users  5952 Nov 12 17:13 /usr/pkg/bin/python2.7
  -rwx---r-x  1 root  users  1685 Nov 12 17:14 /usr/pkg/bin/python2.7-config
  lrwxr-xr-x  1 root  wheel     9 Jan 18  2018 /usr/pkg/bin/python3 -> python3.6
  -rwx---r-x  1 root  users  7728 Feb  9  2018 /usr/pkg/bin/python3.6
  -rwx---r-x  1 root  users  3132 Feb  9  2018 /usr/pkg/bin/python3.6-config
  -rwxr-xr-x  1 root  wheel  5984 Dec 24 01:27 /usr/pkg/bin/python3.7
  -rwxr-xr-x  1 root  wheel  3132 Dec 24 01:27 /usr/pkg/bin/python3.7-config

They seem to use the "users" group to deny execute access to members of that group, but they have some more recently installed/updated packages that they haven't applied such permissions to.

There is the additional membership level MetaARPA, at $9/month which you need to have to have access to tools like git:

  $ ls -l /usr/pkg/bin/git
  -rwxr-x---  1 root  MetaARPA  2481424 Sep 11 13:50 /usr/pkg/bin/git

The motd mentions that they're testing a NetBSD 8 upgrade right now, which may be why the permissions aren't set up correctly for some of the tools that are supposed to be restricted at the "user" level.

But anyhow, this kind of restriction of use of basic development tools for the free tier makes it kind of useless for what I wanted to use it for, even if the restriction isn't enforced all that well. I could understand if they restricted usage, like disk or CPU, or things like TLS for your home page, and I can understand restricting some outbound networking to prevent abuse, but not providing access to Python and Git in the free tier?

One other benefit of experiencing this system instead of a random cloud VM is that one can experience what a properly managed 'classic' unix system is like - e.g:

- multinode / shared nfs homedirs / multiuser

- CLI mail is wired up properly

- publish www via ~/public_html

- finger/whois

- system from source, 3rd party stuff in ports

the modern 'random ubuntu laptops + dhcp on wifi' network feels hugely impoverished by comparison as far as network cohesion (but yes there are positives to this tradeoff too)

cli mail, finger and talk could be a great initiation to traditional tools!

As for the random ubuntu laptops, try to do the dhcp on wifi using a debootstrap of a minimal debian on a separate partition, then configure wpa_supplicant to start dhcp by systemd dependancy, and detect wifi card to start wpa_supplicant@wifi_card_device_name. This could give you a great introduction to modern tools! (bonus points if you setup a native wayland)

Understand the old and the new ways gives a better picture of the overall system, and will help you make education decisions.

(And it's not forbidden to setup CLI mail on your modern system, or a systemd-based classic unix! mix and match to your tastes!)

I suppose this shows my age; for me, it will always be sdf.lonestar.org and the fastest way to get a better access level will be to take a hardware donation to an address in a suburb of Dallas.

(I wonder if my account still works...wow, it does. I should really change that password.)

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