One of the things people put in their HTTP User-Agent header fornon-browser software is a URL for their software, project, orwhatever ( I'm all for this ). This is a agood thing, because it allows people operating web servers to checkout who and what you are and decide for themselves if they're goingto allow it. Increasingly (and partly for social reasons ), I block many 'generic' User-Agentvalues that come to my attention, for example

The other day I covered how I think systemd's IPAddressAllow andIPAddressDeny restrictions work , whichunfortunately only allows you to limit this to specific (local)ports only if you set up the sockets for those ports in a separate systemd.socket unit. Naturally this raises the question of whether there is a good,scalable way to restrict access to specific ports in eBPF thatsystemd (or other interested parties) could use. I think the answeris yes, so here is a sketch of how I think you'

I recently wrote about things that make me so attached to xterm . One of those things is xterm's ziconbeepfeature , which causes xterm to visiblyand perhaps audibly react when it's iconified or minimized and getsoutput. A commentator suggested that this feature should ideallybe done in the window manager, where it could be more general.Unfortunately we can't do the equivalent of ziconbeep in the windowmanager, or at least we can't do all of it.

A window manager can sound an audible

Among the systemd resource controls are IPAddressAllow= and IPAddressDeny= ,which allow you to limit what IP addresses your systemd thing caninteract with. This is implemented with eBPF .A limitation of these as applied to systemd .service units is thatthey restrict all traffic, both inbound connections and things yourservice initiates (like, say, DNS lookups), while you may wantonly a simple inbound connection filter .However, you can also set these on systemd.socket units. If you do, your IP address restrictions

I have a Python program that calculates and prints various piecesof Linux memory information on a per-cgroup basis. In the beginning,its life was simple; cgroups had a total memory use that was splitbetween 'user' and '(filesystem) cache', so the program only neededto display either one field or a primary field plus a secondaryfield. Then I discovered that there was additional important(ie, large) kernel memory use in cgroups and added the ability toreport it as an additional option

One of my long standing gripes with Debian and Ubuntu is, well, I'll quote myself on the Fediverse :

I understand that Debian wants me to use 'apt' instead of apt-get,but the big reason I don't want to is because you can't turn off thatprogress bar at the bottom of your screen (or at least if you canit's not documented). That curses progress bar is something that Iabsolutely don't want (and it would make some

I recently read Evan Hahn's The two kinds of error ( via ), which talks verybriefly in passing about logging, and it sparked a thought. I'vepreviously written my system administrator's view of what an errorlog level should mean , but that entryleaves out something fundamental about log messages, which is thatunder most circumstances, log messages are for the people operatingyour software ( I've sort of said this before in a differentcontext ). When you're about to add

I've said before in various contexts ( eg )that I'm very attached to the venerable xterm as my terminal(emulator) program, and I'm not looking forward to the day that Imay have to migrate away from it due to Wayland (although I probablycan keep running it under XWayland, now that I think about it). ButI've never tried to write down a list of the things that make meso attached to it over other alternatives like urxvt, much lessmore

Back when we had just started with our current metrics anddashboards adventure , I wrote abouthow sometimes the simplest version of a graph is a text table . Today I will extend that further: sometimesthe simplest version of a text table is to have a command thatprints it out, rather than making people look at a web page.

We recently had a major power outage at work , and in theaftermath not all of our machines came back .One of my co-workers is an extreme early bird and he