198 Matching Annotations
  1. Apr 2024
  2. Mar 2024
    1. If you want to write an awk script, which portable to any awk implementations and versions (gawk/nawk/mawk...) it is really hard, even if with --posix (gawk)
    1. The function body can be any compound command, not just a group command ( {} ). Use a sub-shell: is_hello_world() ( shopt -s nocasematch [[ "$1" =~ "hello world" ]] )
    2. foo () {...} just looks so natural, you never think that the braces aren't part of the function syntax, rather than the mostly commonly used compound command.
    3. I suppose it would be easy to make a pushshopt function like there is a pushd, and use bash arrays to remember previous option before setting them. Like pushshopt +extglob -nocasematch and popshopt
    1. Die Gewinne von Shell sind 2023 auf 28 Milliarden Dollar gesunken; 2022 hatten sie 40 Milliarden Dollar betragen. Trotzdem war 2022 eines der erforlgreichsten Jahre der Firmengeschichte; die Dividenden sollen erhöht werden. Greenpeace reagierte mit einer satirischen Party, bei der die Verbrennung der Zukunft gefeiert wird. U.a. mit Projekten in Brasilien und im Golf von Mexiko setzt Shell die fossile Expansion fort. https://www.theguardian.com/business/2024/feb/01/shell-to-raise-dividends-again-despite-30-fall-in-annual-profits

    1. Shell plant nicht mehr, seine Öl-Produktion bis 2030 wenigstens um 1-2% pro Jahr zu reduzieren. Zwischen 2023 und 2035 will die Firma jährlich 40 Milliarden Dollar in die Öl-und Gasproduktion und 10-15 Milliarden in „Low-Carbon“-Produkte investieren. Die Ölproduktion soll bis 2030 stabil bleiben, die Gasproduktion ansteigen. Shell beruft sich auch darauf, dass man 2021 die Anteile an einem Projekt im Permian Basin verkauft und damit die Ölproduktion früher als geplant bereits gedrosselt habe. https://www.theguardian.com/business/2023/jun/14/shell-drops-target-to-cut-oil-production-as-ceo-guns-for-higher-profits

    1. Shell will die Emissionsintensität seiner Öl-Produkte bis 2030 nur noch um 15-20% statt bisher um 20% reduzieren. Das verfässerte Ziele ist in der jüngsten Version der Energiewende-Strategie des Konzerns enthalten, die einen Teil des Jahresberichts 2023 bildet. Für Gas wurden keine Angaben gemacht. Auch für die absolute Höhe der Emissionen gibt der Fossilkonzern kein Ziel an. Durch neue Projekte wird Shell seine Öl- und Gasproduktion bis 2025 um 500.000 Barrel täglich steigern.

      https://www.theguardian.com/business/2024/mar/14/shell-warns-it-may-slow-emissions-reduction-during-crucial-climate-decade

    1. nowadays many people work with docker containers. Most default docker images do not have bash and something like [[ $string == *foo* ]] will not work.
    2. It's not so much a criticism as the preference of a more universal solution over a more limited one. Please consider that, years later, people (like me) will stop by to look for this answer and may be pleased to find one that's useful in a wider scope than the original question. As they say in the Open Source world: "choice is good!"
  3. Feb 2024
  4. Jan 2024
    1. Eine neue, grundlegende Studie zu Klima-Reparationen ergibt, dass die größten Fosssilkonzerne jählich mindestens 209 Milliarden Dollar als Reparationen an von ihnen besonders geschädigte Communities zahlen müssen. Dabei sind Schäden wie der Verlust von Menschenleben und Zerstörung der Biodiversität nicht einberechnet. https://www.theguardian.com/environment/2023/may/19/fossil-fuel-firms-owe-climate-reparations-of-209bn-a-year-says-study

      Studie: Time to pay the piper: Fossil fuel companies’ reparations for climate damages https://www.cell.com/one-earth/fulltext/S2590-3322(23)00198-7

    1. Guter Überblick über das Lobbying-Netzwerk der deutschen Gasindustrie. Der Verbraucht an Erdgas hat sich in Deutschland seit 1990 verdoppelt, obwohl Erdgas insgesamt etwa so viel Emissionen verursacht wie Kohle. Die LNG-Infrastruktur, die die deutsche Bundesregierung gerade aufbaut, ist auf um ein Drittel höhere Kapazitäten angelegt, als aus Russland importiert wurden. https://taz.de/Fossile-Politik/!5983492/

    1. Norwegen erteilt in diesem Jahr 62 Lizenzen für die Exploration von Öl- und Gasfeldern, gegenüber 47 im vergangenen Jahr. Die Steigerung geht auf das Interesse von Öl- und Gasgesellschaften zurück. Gegen den Widerstand von NGOs betreibt Norwegen weiterhin eine Ausweitung der Öl- und Gasproduktion, die zu jahrzehntelanger Förderung führen soll. Stark gewachsen ist dabei das Interesse an der Barents Sea. https://www.reuters.com/business/energy/norway-increases-number-new-oil-gas-drilling-permits-including-arctic-2024-01-16/

    1. BP, Shell, Chevron, ExxonMobil et TotalEnergies werden an ihre Aktionäre für das Jahr 2023 mehr als 100 Milliarden Dollar Dividenden auszahlen und damit den Rekord des Vorjahres noch übertreffen. Ursachen für die Rekordprofite sind der Krieg in der Ukraine und die Umwälzungen auf den Weltenergiemärkten. Die Konzerne gehen weiterhin von der Profitabilität ihres Geschäfts aus. Weltweit leiden ärmere Haushalte unter den gestiegenen Energiekosten. https://www.liberation.fr/environnement/climat/industries-fossiles-les-petroliers-arrosent-leurs-actionnaires-de-dividendes-records-20240102_KETOFCVOT5ANLNWCBWMGNYOE7I/

  5. Dec 2023
    1. Reclaim Finance zufolge ist 2022/23 die Finanzierung von 437 Öl- und Gasprojekte genehmigt worden. Beteiligt sind 200 Unternehmen in 58 Ländern. Die Projekte widersprechen der Roadmap der IEA zur Klimaneutralität von 2021, in der keine neuen fossilen Projekte vorgesehen sind. Eine Schlüsselrolle haben staatliche Firmen in Öl und Gas produzierenden Staaten. Bei der Zahl der Projekte liegen Russland und Norwegen vorne. Europäische Ölgesellschaften haben eine Reduzierung ihrer (unzureichenden) Dekarbonisierungsziele angekündigt. https://www.liberation.fr/environnement/437-nouveaux-projets-petroliers-et-gaziers-quels-sont-les-pays-moteurs-des-energies-fossiles-en-2023-20231130_QRXDTQKM7NBIZGXWUNFQ7QRSWM/

    1. Einer Greenpeace-Studie zufolge werden die Treibhausgasemissionen von 9 großen europäischen Fossilkonzernen (darunter auch die OMV) im Jahr 2022 zu mindestens 360.000 vorzeitigen Todesfällen allein aufgrund von Extremtemperaturen führen. Dabei gehen die Autor:innen aufgrund einer Übersichtsstudie davon aus, dass 9.318 Tonnen CO<sub>2</sub> im Jahr 2020 statistisch gesehen zu einem zusätzlichen Todesfall bis 2100 führen werden. https://taz.de/Studie-zu-Fossilkonzernen/!5978273/

      Studie: https://www.greenpeace.org/nl/todaysemissionstomorrowsdeaths/

    1. Dichter und sehr gut dokumentierter Überblicksratikel über die Expansionspläne der Öl- und Gasindustrie. Aus unerschlossenen Feldern sollen 230 Milliarden Barrel Öläquivalent gefördert werden - im klaren Widerspruch zum Pariser Abkommen. Durch Ausbeutung neuer Lager werden bis 2025 voraussichtlich 70 Gt CO<sub>2</sub> und damit 17% des Budgets für das 1,5° Ziel ausgestoßen. Eingegangen wird auch auf den Ausstiegsplan des Tyndall Centre. https://taz.de/Run-auf-fossile-Brennstoffe/!5973686/

  6. Nov 2023
    1. Seit dem Pariser Abkommen haben europäische Banken fossile Energieunternehmen durch die Ausgabe vom Anleihen in Wert von ca einer Billion (1000 Milliarden) Euro unterstützt, wie eine Recherche des Guardian ergibt. Anleihen (Bons) sind inzwischen die wichtigste Form der Finanzierung der Fossilindustrie. https://www.theguardian.com/business/2023/sep/26/europes-banks-helped-fossil-fuel-firms-raise-more-than-1tn-from-global-bond-markets

  7. Oct 2023
    1. Der italienische Energiekonzern ENI wird über die bestehenden Verträge hinaus über 27Jahre bis zu 1 mtpa (Million Tonnen pro Jahr) LNG aus Qatar beziehren. Vorangegangen waren ähnliche Deals über jährlich 3,5 mtpa über 27 Jahre mit Shell und TotalEnergies. Ein Deal von QatarEnergy und ConocoPhilips vom November 2022 sieht vor, dass Deutschland ab 2026 über 15 Jahre 2 mtpa LNG bezieht. Ähnliche Abkommen schloss QatarEnergies auch zurLNG-Versorgung asiatischer Länder ab. https://www.reuters.com/markets/commodities/qatar-signs-27-year-gas-supply-deal-with-italys-eni-2023-10-23/

  8. Sep 2023
    1. commands="\nthing1@this is thing 1\!\nthing2@this is thing 2!" while read line;do // do your stuff here line <<< $( echo -e "${commands}" )

      Seems to work. Not used to the <<< expression...

    1. Also, always prefix globs with "/" or "./"; otherwise, if there's a file with "-" as the first character, the expansions might be misinterpreted as options.
  9. Aug 2023
  10. Jun 2023
  11. May 2023
  12. Apr 2023
  13. Feb 2023
    1. De UvA gaat voorlopig geen nieuwe onderzoekssamenwerkingen met Shell of soortgelijke bedrijven aan.

      UvA gaat voorlopig geen nieuwe onderzoekssamenwerkingen met Shell of soorgelijke bedrijven aan.

  14. Dec 2022
    1. For sufficiently simple cases, just running a few commands sequentially, with no subshells, conditional logic, or loops, set -euo pipefail is sufficient (and make sure you use shellcheck -o all).

      Advice for when you can use shell scripts

  15. Nov 2022
    1. Bash maintains an internal hash of previously found executables in your path. In this case, it has details that at one time there was an executable at /usr/bin/siege, and reuses that path to avoid having to search again. You need to tell bash to manually rehash the path for siege like so: hash siege You can also clear all hashed locations: hash -r
    1. Remember there are two kinds of variable. Internal Variables and Environment Variables. PATH should be an environment variable.

      In my case, I was trying to debug which asdf not finding asdf, in a minimal shell.

      I had checked bash-5.1$ echo $PATH|grep asdf /home/tyler/.asdf/bin

      but ```

      The PATH environment variable

      env | /bin/grep PATH `` being empty was the key discovery here. Must have forgotten theexport`.

    2. All shells should tell you that your path is the same thing with BOTH of the two commands: # The PATH variable echo "$PATH" # The PATH environment variable env | /bin/grep PATH
    1. Auch der Standard weist in einem Halbzeitbericht zur COP27 darauf hin, wieviele Vertreter der Fossilindustrien an den Verhandlungen dürfen. Ein Hauptinteresse dabei ist es, durch Regeln zu verhindern, dass die selbst verursachten Emissionen wirksam reduziert werden müssen. Er verweist dabei auf Shells Einfluss bei der Formulierung des Aktikels 6 des Pariser Abkommens.

  16. Aug 2022
    1. “These ads are intended to create a clean warm glow about the companies concerned, giving them more social licence to operate,” said Doug Parr, chief scientist for Greenpeace UK

      Die Ausgaben sprechen dafür, dass diese Art von Kommunikation sehr wirksam ist. Auch das schafft eine fundamentale Assymetrie zwischen der Fossilindustrie und ihren Gegnern.

    1. $0 would be OK in most cases, some exceptions are, for instance, when the script you're executing is aliased (through alias in .bash_profile). You should really use $BASH_SOURCE variable, instead of $0.
    2. Using $0 does not work when the script is run using source script or . script; the name of the script is not available.
  17. Jul 2022
    1. Always use a while read construct: find . -name "*.txt" -print0 | while read -d $'\0' file do …code using "$file" done The loop will execute while the find command is executing. Plus, this command will work even if a file name is returned with whitespace in it. And, you won't overflow your command line buffer.
  18. Apr 2022
    1. You can close the single quotes before starting the double quotes and do the reverse at the end of that inner section to achieve what you want:

      This is how to use variable in single quotes. It works well also for tcsh.

  19. Mar 2022
    1. Just let it expand inside an array declaration's right side: list=(../smth*/) # grab the list echo "${#list[@]}" # print array length echo "${list[@]}" # print array elements for file in "${list[@]}"; do echo "$file"; done # loop over the array
  20. Feb 2022
  21. Sep 2021
    1. I think it's very confusing to overload common executables, such as yarn, in the /bin directory as I often put that bin directory first in my path. Thus, I'd unexpectedly get the bin/yarn rather than my system yarn, which I manage with yvm.
    1. One good use for /dev/tty is if you're trying to call an editor in a pipeline (e.g., with xargs). Since the standard input of xargs is some list of files rather than your terminal, just doing, e.g., | xargs emacs will screw up your terminal. Instead you can use | xargs sh -c 'emacs "$@" </dev/tty' emacs to connect the editor to your terminal even though the input of xargs is coming from elsewhere.
  22. Jun 2021
    1. Please make sure that your file(s) referenced in bin starts with #!/usr/bin/env node, otherwise the scripts are started without the node executable!
    1. Since looping over the positional parameters is such a common thing to do in scripts, for arg defaults to for arg in "$@". The double-quoted "$@" is special magic that causes each parameter to be used as a single word (or a single loop iteration). It's what you should be using at least 99% of the time.
    2. Bash (like all Bourne shells) has a special syntax for referring to the list of positional parameters one at a time, and $* isn't it. Neither is $@. Both of those expand to the list of words in your script's parameters, not to each parameter as a separate word.
    1. Instead of using a for loop, which will fail on spaces unless you redefine the IFS variable, I would recommend using a while loop combined with find.
    1. Different ways to prepend a line: (echo 'line to prepend';cat file)|sponge file sed -i '1iline to prepend' file # GNU sed -i '' $'1i\\\nline to prepend\n' file # BSD printf %s\\n 0a 'line to prepend' . w|ed -s file perl -pi -e 'print"line to prepend\n"if$.==1' file
    1. for cpp_file in *.cpp; do gcc -c $$cpp_file & done; wait This gives much finer control than make -j.
    2. There is one very important reason for enabling job control to be useful inside scripts: the side-effect it has of placing background processes in their own process groups. This makes it much, much easier to send signels to them and their children with one simple command: kill -<signal> -$pgid. All other ways of dealing with signaling entire trees of processes either involve elaborate (sometimes even recursive) functions, which are often bugnests, or risk killing the parent in the process (no pun intended).
    1. To avoid the problems with different versions of echo you may want to use printf instead. In contrast to echo printf always interprets \ sequences but doesn't automatically add a linefeed at the end so you have to append \n at the end if you want one.
    1. while (( "$#" )); do case "$1" in -a|--my-boolean-flag) MY_FLAG=0 shift ;; -b|--my-flag-with-argument) if [ -n "$2" ] && [ ${2:0:1} != "-" ]; then MY_FLAG_ARG=$2 shift 2 else echo "Error: Argument for $1 is missing" >&2 exit 1 fi ;; -*|--*=) # unsupported flags echo "Error: Unsupported flag $1" >&2 exit 1 ;; *) # preserve positional arguments PARAMS="$PARAMS $1" shift ;; esacdone# set positional arguments in their proper placeeval set -- "$PARAMS"
  23. May 2021
    1. For filter-branch, using pipelines like git ls-files | grep -v ... | xargs -r git rm might be a reasonable workaround but can get unwieldy and isn't as straightforward for users; plus those commands are often operating-system specific (can you spot the GNUism in the snippet I provided?)
    1. However, the place where pip places that package might not be in your $PATH (thus requiring you to manually update your $PATH afterwards), and on windows the pip install might not take care of python-specific issues for you (see "Notes for Windows Users", above). As such, installation via package managers is recommended instead.
    1. the bullet-proof way to add a path (e.g., ~/opt/bin) to the PATH environment variable is PATH="${PATH:+${PATH}:}~/opt/bin"
    1. The command nix-shell will build the dependencies of the specified derivation, but not the derivation itself. It will then start an interactive shell in which all environment variables defined by the derivation path have been set to their corresponding values, and the script $stdenv/setup has been sourced. This is useful for reproducing the environment of a derivation for development.

      QUESTION: What exactly does nix-shell execute from the Nix expression (i.e., shell.nix, default.nix, etc.)?

      ANSWER: Based on my current understanding, the answer is everything. It calls $stdenv/setup (see annotation below) to set up the most basic environment variables (TODO: expand on this), and "injects" the most common tools (e.g., gcc, sed) into it.

      It also defines the phases (TODO: verify this) and builder functions, such as genericBuilder. For example, the default builder is just two lines:

      source $stdenv/setup
      genericBuild
      

      TODO: pkgs/stdenv/generic/builder.sh is a mystery though.

      QUESTION: Once dropping into nix-shell, how do I know what phases to execute by looking at a default.nix? (E.g., [..]freeswitch/default.nix)

      ANSWER: As far as I can tell, one can override the phases in their Nix build expression (to build the derivation, see at the bottom), but they won't get executed as only the $stdenv/setup (see above) will get sourced, and no builders are called that, in return, invoke the phases (again, see above).

      So if one is using nix-shell

      • to create/hack on a package, the person has to manually invoke the builder or phases (TODO: still fuzzy on this subject)

      • to set up an environment, then one doesn't even have to worry about builders/phases because we just use nix-shell to clear the environment and to inject tools that we need for a given task

      QUESTION: When dropping into nix-shell, is this Nix expression (i.e., freeswitch/default.nix) executed? Or just parts of it?

      ANSWER: As stated above, all of the input Nix expression is evaluated, but no builders and build phases are called; although, nothing prevents one to override the phases, in case they are creating/hacking on a package.

      QUESTION:

      The command nix-shell will build the dependencies of the specified derivation, but not the derivation itself.

      What is the "derivation" here exactly? I know that it is a build expression, but does that mean the default.nix (or other Nix expression) nix-shell is invoked with?

      <sup>This statement also seems like a contradiction with how `nix-shell` works (i.e., if one issues `nix-shell -p curl`, then `curl` will be available in that sub-shell), but `-p` acts like a shortcut to as if `curl` had been listed in `buildInputs` so this is not the case.</sup>

      ANSWER: I have the feeling my confusion comes from the fact that the term "derivation" is used ambiguously in the manuals, sometimes to mean multiple things (see list below).

      TODO: Substantiate this claim, and make sure that it not coming from my misunderstanding certain topics.

      • Nix build expression (such as default.nix) whose output is going to become the store derivation itself (see last item at the bottom about the Nix manual's glossary definition)

      • store derivation.

      Had multiple cracks at unambiguously define what a derivation is, and here's a list of these:

      QUESTION: What is the difference between nix-shell -p and nix-shell invoked with a Nix expression of mkShell (or other that achieves the similar effect)?

      QUESTION: nix-shell does not create a sub-shell, so what does it do? (clarification: so nix-shell indeed does it; I confused it with nix shell)

  24. Apr 2021
    1. Write stderr and stdout to a file, display stderr on screen (on stdout) exec 2> >(tee -a -i "$HOME/somefile.log") exec >> "$HOME/somefile.log" Useful for crons, so you can receive errors (and only errors) by mail
    2. I just wanted to point out that the syntax is not supported by the POSIX standard and thus won't universally work in /bin/sh scripts (many people erroneously use bash syntax in /bin/sh scripts)
    3. exec > >(tee "$HOME/somefile.log") 2>&1
    1. When you have a pipeline, unbuffer must be applied to each element except the last (since that doesn't have its output redirected). Example: unbuffer p1 | unbuffer p2 | unbuffer p3 | p4
    1. empty is an utility that provides an interface to execute and/or interact with processes under pseudo-terminal sessions (PTYs). This tool is definitely useful in programming of shell scripts designed to communicate with interactive programs like telnet, ssh, ftp, etc.
    2. can be easily invoked directly from shell prompt or script

      Can't expect / unbuffer / etc. (whatever this is attempting to contrast itself with) be easily invoked directly from shell prompt or script too??

      Okay, I guess you have to know more about how expect is invoked to understand what they mean. One glance at the examples, comparing them, and all becomes clear:

      #!/bin/sh
      empty -f -i in -o out telnet foo.bar.com
      empty -w -i out -o in "ogin:" "luser\n"
      

      I didn't realize that expect required/expected (no pun intended) to be used in scripts with its own shebang line:

      #!/usr/bin/expect
      
      spawn telnet foo.bar.com 
      expect ogin {send luser\r}
      

      That does make it less easy/normal to use expect within a shell script.

      I was coming to the expect project from/for the unbuffer command, which by contrast, is quite easy to include/use in a shell script -- almost the same as empty, in fact. (Seems like almost a mismatch to have unbuffer command in expect toolkit then. Or is expect command the only odd one out in that toolkit?)

    3. does not use TCL, Perl, PHP, Python or anything else as an underlying language is written entirely in C has small and simple source code can easily be ported to almost all UNIX-like systems
  25. Mar 2021
  26. Feb 2021
    1. Now this probably won't make difference in the real world (e.g. because the exit codes are not portable and on top of that not always unambiguous as discussed in Default exit code when process is terminated?)
    1. read -rep $'\nDo you wish to stop playing?(y/n)' yn
    2. You also need job controlled -monitoring in your parent so it keep track of its children. wait, for example, only works at all with job control. -monitor mode is how shells interact with terminals.