Folkert van Heusden writes about his own software projects, including MultiTail, entropy tools, and an SGI Indy emulator.
Commenters recommend his multitail utility for following multiple log files with regex highlighting, and compare other tools to it.
If you need more entropy for SSL traffic than a headless server that sees very little I/O load has available, I've found http://www.vanheusden.com/te/ useful in the past. The ~800 bits/sec is produced in our tests isn't massive, but it was considerably than the machines we used it on could generate from the kernel's usual sources on these machines. It claims to produce valid results in VMs too, and given the way it works it might be perfectly valid to scale is some way simply by running more than one copy.
If you want more than that in a cheap Heath Robinson manner (Americans: think Rube Goldberg if you are unaware of Heath, their work came from very similar inspirations) then many SoC solutions have a built-in RNG of sufficient quality for general cryptographic use and some solutions expose them easily. If you enable the relevant module a Raspberry Pi can provide up to ~550,000 bits/sec when asked to, for instance, which if one-off cost is a factor beats paying a few hundred dollars or more for a USB device providing the same sort of rate.
You could also just send output to separate files by re-opening stdout/stderr and use https://www.vanheusden.com/multitail/index.html (or GNU screen or tmux or whatever) to multiplex a terminal in a more organized way. This also solves an "open problem" in the article of stray prints.
If you really want to share one terminal / stdout but also prevent timing-based record splitting, you could also send outputs to FIFOs / named pipes and then have a simple record boundary honoring merge program like https://github.com/c-blake/bu/blob/main/funnel.nim with doc at https://github.com/c-blake/bu/blob/main/doc/funnel.md As long as "record format" is shared (e.g. newline-terminated) this can also solve the stray print problem.
I was going to mention multitail as well, which is a fantastic utility. That and rsstail, both by Folkert Van Heusden, are quite slick. The mark it leaves (a red line across the screen) is even more visible than those given by less.
I've commented a bit more on them (in the context of other RSS tools) here:
https://www.reddit.com/r/dredmorbius/comments/1udv6i/further_adventures_in_rss_chrome_reader_extension/
Folkert's site: http://www.vanheusden.com/ http://www.vanheusden.com/multitail/ http://www.vanheusden.com/rsstail/
Though not quite applicable to logfiles, I've written a script to tail my Newsbeuter feed URLs with Multitail support, for a console / terminal-based RSS feed.
> That's where this program is for: adding entropy-data to the kernel-driver. It does that by fetching 2 images from a video4linux-device (with a random delay in between), calculating the difference between those two and then calculating the number of information-bits in that data. After that, the data with the number-of-entropy-bits is submitted to the kernel-random-driver.
http://www.vanheusden.com/ved/
There's also an "audio" version of, basically, the same thing [0] that I intend on using in the near future. It's as simple as tuning an FM radio to "nothing" and connecting its headphone/line out to your sound card's input line.
[0]: http://www.vanheusden.com/aed/
Entropy in VMs is hard to get, it's nice to see an "easy" way to access better system-level entropy. There are also a few utils that let you distribute entropy amongst your VMs[1], but getting everything directly from the system feels better from a security perspective.
I've been forced to use rng-tools and / or rng-usleep to get enough randomness in some Ubuntu VMs in the past. It's maddening to see SSL slowdowns for no good reason, and to have to trace it back to a blocking call to /dev/random for 8 lousy bytes.
[1] http://www.vanheusden.com/Linux/#security
mboxstats[1] is pretty good for this if you're fetching the monthly archives from the web interface and desire a quick overview. It supports mbox and maildir, and can produce XML output for easier post-processing.
The mboxstats author has a variety of interesting tools on his site, if you're in to strange stats and log processing like me ;)
I've submitted it here[2] in the hope others pile in with other cool options.
1. http://www.vanheusden.com/mboxstats/
2. https://news.ycombinator.com/item?id=13418463