Process substitution is available in ksh, bash, and zsh.
More examples can be found here: Process Substitution.
Process substitution uses /dev/fd/<n> files to send the results of the process(es) within parentheses to another process.
Piping the output of one program to the input of another…
Today, 14-Oct-2024, starting at 16:23 (CET), internet provided by Vodafone was unavailable.
At 20:51 internet was available again.
So for almost five hours I had no internet and the blog went dark.
Luckily, the IP address stayed the same, so I had no delay in DNS.
DOCSIS signal noise ratio is now…
I wrote about hosting static sites on various platforms:
Hosting Static Content with surge.sh
Hosting Static Content with now.sh, now.sh renamed themself to vercel.app
Hosting Static Content with netlify.app
Hosting Static Content with Cloudflare
Hosting Static Content with Neocities
Hosting…
Our solar system is not stable when considerung time ranges of several Gigayears. These are the results of simulations done by Laskar and Gastineau.
1. Nomenclature
Notions for ellipses, see below figure:
center M
semi-minor axis b
semi-major axis a
(linear) eccentricity e, numerical eccentricity…
XHProf is a PHP profiler.
I had written on XHProf here:
Profiling PHP Programs
Profiling PHP Programs #2
XHProf was originally written by Facebook engineers.
Even though it severely slows down your PHP program during execution, it is nevertheless a valuable tool to get an understanding, where…
Authors: Roman Edenhofer and Simon Apers
Université Paris Cité, CNRS, IRIF, Paris, France
Abstract
1. Introduction and summary
Counting few paths
Unambiguity, Fewness and a language in $\mathsf{BQL}$ (maybe) not in $\mathsf{BPL}$
Conclusion and open questions
2. Space-bounded computation
2.1…
SSHGuard is a software to block unwanted SSH login attempts.
SSHGuard has a very remarkable architecture: it has a set of independent programs doing parsing, block-indication, and actual blocking.
I wrote about this in Analysis And Usage of SSHGuard.
SSHGuard 2.4.3 is about 100kLines of C and shell…
1. The post Hosting Static Content with GitLab was mentioned on Hacker News and this site experienced a heavy increase in accesses.
Neither PHP, nor NGINX, nor the ISP experienced any problems.
Nevertheless, I had never before seen such a stark rise in accesses to this website with real…
1. Notation
2. Example Runge-Kutta methods
3. Local discretization error
4. Order condition
5. Power series expansion for global error
6. Cauchy product formula
7. Recursive calculation of the order condition
Below text is based on the results in
Peter Albrecht: "A New Theoretical Approach…
I wrote about hosting static sites on various platforms:
Hosting Static Content with surge.sh
Hosting Static Content with now.sh, now.sh renamed themself to vercel.app
Hosting Static Content with netlify.app
Hosting Static Content with Cloudflare
Hosting Static Content with Neocities
Hosting…
I wrote about hosting static sites on various platforms:
Hosting Static Content with surge.sh
Hosting Static Content with now.sh, now.sh renamed themself to vercel.app
Hosting Static Content with netlify.app
Hosting Static Content with Cloudflare
Hosting Static Content with Neocities
GitLab…
1. Konsistenz, Konsistenzordnung und Fehlerkonstanten
2. Die Anwendung linearer Mehrschrittverfahren bei DAE
3. Mehrere Charakterisierungen der Konsistenzordnung
4. Die erste Dahlquist-Barriere
5. Die zweite Dahlquist-Barriere
6. Annullierte Dominanz und Totalannullation
7. Das $n$-dimensionale…
1. Semistabilitätsfunktionale in Matrixdarstellung
2. Bemerkungen zum Spijkerschen Stabilitätsfunktional
1. Semistabilitätsfunktionale in Matrixdarstellung
Mit Ausnahme der Booleschen Algebra wird keine Theorie in der Mathematik
universeller benutzt als die lineare Algeba.
Es gibt kaum eine…
1. Das modifizierte Newton-Verfahren und Spezialisierungen
2. Die Divergenzsätze von Hughes Hallett
3. Die Experimente von Byrne/Hindmarsh/Jackson/Brown
Einer der ganz zentralen Bestandteile eines Programmes, basierend auf
Verfahren mit impliziten Stufen, ist die Auflösung der…
1. Einführung und grundlegende Begriffe
2. Die Lemmata von Gronwall
3. Notation und Darstellungssatz für Differenzengleichungen
4. Stabilitätsfunktionale für feste Schrittweiten
5. Projektorstabilitätsfunktionale
6. Nichtäquidistante Gitter
7. Die Eigenwerte gewisser tridiagonaler…
1. Konditionszahlen von Matrizen
2. Elementare Zeilen- und Spaltenoperationen
3. Die $LU$-Zerlegung
4. Die Gauß-Elimination
Bei jedem Iterationsschritt eines Newton-Raphson-Verfahrens, bzw. bei
jeder Aktualisierung der Iterationsmatrix beim
Newton-Kantorovich Iterationsverfahren, fällt die…
1. Projektor
Sei eine lineare Mannigfaltigkeit ${\cal M}\subseteq\mathbb{C}^n$ aufgespannt
durch die $s$ linear unabhängigen Vektoren
$a_1,\ldots,a_s\in\mathbb{C}^n$.
Sei $A=(a_1,\ldots,a_s)\in\mathbb{C}^{n\times s}$.
Es gilt
$$
% Mehrfache Indizes für Minoren:
% #1: Anzahl der Indizes, #2:…
I turned 60 this year. I had written a similar post ten years ago: Turning 50 - Now what?
What has happened in the last ten years?
The last time I wrote:
I am married and have three children. All three children show interest in society and technology, and will likely find their way through life.…
This blog offered to switch betwen light and dark mode.
But this choice was not stored anywhere.
So any page you clicked on, you had to choose dark mode again.
Now I store this choice in localStorage on the client.
While cookies could also be used for storing this choice, they are not needed for…
I stumbled on below error message from the IBM COBOL compiler for mainframe:
IGYRC5108-U COBOL COMPILER TERMINATING: UNCORRECTABLE PROGRAM INTERRUPT CONDITION.
The COBOL program was not fully compiled but compilation stopped midway.
Further messages from the compile run:
PROGRAM CHECK,…