I think you can only truly appreciate ed when you were forced to use a DECwriter as your terminal because all the VT100s were in use.  (Undergrad student lab)

Michael Usher
Network Operations Manager
University of California, Santa Cruz
musher@ucsc.edu        831-459-3697

On Mar 29, 2021, at 12:50 PM, Rob Pike <robpike@gmail.com> wrote:

Ed is the standard editor.


On Tue, Mar 30, 2021 at 1:36 AM Larry McVoy <lm@mcvoy.com> wrote:
I had *.clients.your-server.de crawling mcvoy.com in violation of my
robots.txt.  For whatever reason, the tty settings (or something)
made vi not work, I dunno what the deal is, stty -tabs didn't help.

So I had to resort to ed to write and debug the little program below.
It was surprisingly pleasant, it's probably the first time I've used ed
for anything real in at least a decade.  My fingers still know it.

+1 for ed.  It's how many decades old and still useful?

#!/usr/libexec/bitkeeper/bk tclsh

        FILE    log = popen("/var/log/apache2/dns.l", "r");
        string  buf, ip;
        string  dropped{string};

        fconfigure(log, buffering: "line");
        while (buf = <log>) {
                unless (buf =~ /([^ ]+\.your-server\.de\.) /) continue;
                ip = $1;
                if (defined(dropped{ip})) continue;
                dropped{ip} = "yes";
                warn("DROP ${ip}\n");
                system("/sbin/iptables -I INPUT -s ${ip} -j DROP");