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matja

1,184 karma · joined December 29, 2018

https://github.com/matja
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matja··on M1 Thunderbolt ports don’t fully support USB 3.1 Gen 2
Were you expecting to be able? The tech specs say "One external display".
matja··on The best engineering interview question I've ever gotten
I'd guess senior level candidates should solve it without copying and pasting, perhaps make sure test cases are present for the behaviour before modifications are made, and then generalize the existing functions. Or, state why adding more functionality on the server side for every type of arithmetic operation would be unnecessary complexity, and instead add support for any type of atomic arithmetic operation with a transaction/UDF approach.
matja··on Converting integers to decimal strings faster with AVX-512
which AVX-512? :) - https://twitter.com/InstLatX64/status/1114141314441011200/ph...
matja··on I became the world's most prolific DJ, using code
To fully appreciate the silence between notes, you must experience the full orchestra version of John Cage's 4'33"
matja··on Hacked GDB Dashboard Puts It All on Display
Being able to enter a debugger on NMI is great because now you can trigger the NMI from any set of hardware conditions too - you can connect logic gates to the address bus to decode a range of addresses, "and" it with the memory write assert pin or IORQ pin and now you have hardware breakpoints for a machine that didn't originally support it.
matja··on A new tool for finding dark matter digs up nothing
Indeed, neutrinos appear to not be completely understood, https://en.wikipedia.org/wiki/List_of_unsolved_problems_in_p... -> ctrl-F
matja··on Connecting a gaming PC to Apple Studio Display
Surely a removable power cord would ruin the whole aesthetic!?
matja··on Lagrange points solved one of physics' biggest problems
I mean, its as unstable as balancing a broom upright on your hand is... unstable but not impossible.
matja··on H.264 is Magic (2016)
You can try with Imagemagick (https://legacy.imagemagick.org/Usage/fourier/#im_fft) :

    for quality in 50 75 90 95 99 ; do
      # FFT
      convert source.png -fft +depth +adjoin source_fft_%d.png
      
      # compress FFT magnitude and phase
      convert source_fft_0.png -quality $quality source_fft_magnitude.jpg
      convert source_fft_1.png -quality $quality     source_fft_phase.jpg
    
      # IFFT
      convert source_fft_magnitude.jpg source_fft_phase.jpg -ift out.$quality.png
    done
matja··on AMD Fires Back with 7 New Chips
$100 USD PCIe 4.0 SSDs exist (e.g. 500GB SN850), which can comfortably run at close to the theoretical limit of PCIe 4.0, bottle-necked on PCIe 3.0.
matja··on AMD Fires Back with 7 New Chips
Is it because the mainboard is not HDMI 2.0 or does not support DSC (Display Stream Compression?) (https://en.wikipedia.org/wiki/HDMI#Refresh_frequency_limits_...). Raven Ridge supports 2.0, but it's down to the mainboard to also support that.
matja··on Who's Attacking My Server?
If fail2ban is theater, so is a firewall, so is SELinux, so are filesystem permissions (a properly configured process would only read/write the files it's supposed to, right?).

If an remote vuln needs some stack-smashing technique that has a low probability of success, fail2ban is going to to slow that down - perhaps in a way that makes it more obvious in logs, buying you time to discover your broken configuration or out of date software. Same way that a firewall buys you time to find that your database is listening on 0.0.0.0.

matja··on Some tiny personal programs I've written
https://en.wikipedia.org/wiki/Law_of_large_numbers
matja··on Apple M1 Ultra
And WRX80 has dedicated chipset lanes (https://www.amd.com/en/chipsets/wrx80), so effectively more PCI-e than EPYC, and bootable NVME RAID support on top.
matja··on M1 Ultra Geekbench Score
Indeed, it is a little faster single core and a little slower in multi-core on average compared to my 24-core Zen 3 EPYC (https://browser.geekbench.com/v5/cpu/compare/13330272?baseli... - which I expect to be slightly slower than the new 24-core Threadripper Pro 5965WX) - certainly comparable in terms of performance. But no word yet on if the M1 Ultra supports ECC RAM or how many PCIe lanes.
matja··on Ask HN: Do you think nuclear armageddon is plausible?
And those are the ones that we know about.

https://en.wikipedia.org/wiki/Vasily_Arkhipov

matja··on An almost perfect rsync over SSH backup script
AFAIK the crucial part of this, is rsync's `--link-dest=DIR` parameter, which hard-links an unmodified file to the respective place in "DIR", rather than making a copy.
matja··on Avoiding the top Nginx configuration mistakes
I remember one of the early "selling points" of nginx was it didn't traverse the directory tree for a .htaccess file to dynamically load config from, for each request, when that was specifically a "selling point" of Apache, which is very useful for shared hosting contexts when users don't have access to change the webserver config.
matja··on I wound up causing a major outage of my services and destroying my home dir
Can also use cachefile=none and the name does not matter at all. Every disk vdev has a unique guid in the ZFS label area. Without the pool cachefile the guid is used to reliably assemble the pool, instead of the kernel device path.
matja··on Littlefs – A little fail-safe filesystem designed for microcontrollers
And there's no specification on how that wear-leveling works (or doesn't work).
matja··on Jo – a shell command to create JSON (2016)
I'm sure it'd be a patch of a few lines to make the type specification mandatory on the command line (I would certainly prefer that also), but it comes down to the opinion of the maintainer if that is wanted or not.
matja··on Jo – a shell command to create JSON (2016)
Agreed, luckily there is a solution ;)
matja··on Jo – a shell command to create JSON (2016)

    jo -- -s a=123 -s b=00123 -s c="$(date)"
    {"a":"123","b":"00123","c":"Sat  5 Feb 21:29:08 GMT 2022"}
What's the issue?
matja··on Jo – a shell command to create JSON (2016)
then use -s :

        jo -- -s opaque_id=001979
        {"opaque_id":"001979"}
matja··on Jo – a shell command to create JSON (2016)
Agree, I was surprised that the cURL feature was considered as it seems to go against the "Do One Thing" and composability points of the UNIX philosophy.
matja··on Jo – a shell command to create JSON (2016)
I like it, very concise but retains all the features you need.

`jq` can construct JSON "safely" from shell constructs, but is rather more verbose - e.g. with the same examples:

        $ jq -n --arg name Jane '{"name":$name}'
        
        $ jq -n \
        --argjson time $(date +%s) \
        --arg dir $HOME \
        '{"time":$time,"dir":$dir}'
        
        $ jq -n '$ARGS.positional' --args spring summer winter
        
        $ jq -n \
        --arg name JP \
        --argjson object "$(
          jq -n \
          --arg fruit Orange \
          --argjson point "$(
            jq -n \
            --argjson x 10 \
            --argjson y 20 \
            '{"x":$x,"y":$y}' \
          )" \
          --argjson number 17 \
          '{"fruit":$fruit,"point":$point,"number":$number}' \
        )" \
        --argjson sunday false \
        '{"name":$name,"object":$object,"sunday":$sunday}'
matja··on Internet outage affected nearly 30k people after Oakland fiber cable was shot
They were trying to shoot the air and missed!?
matja··on Unicode Normalization Forms: When ö ≠ ö
ZFS can support normalization also:

    $ echo test > $'\xc3\xb6'
    $ cat $'\x6f\xcc\x88'
    cat: ö: No such file or directory

    $ zfs create -o normalization=formD pool/dataset
    $ echo test > $'\xc3\xb6'
    $ cat $'\x6f\xcc\x88'
    test
matja··on Two lines of CSS that will improve HN on mobile (IMO)
12pt = 1em, so how would using em be different?
matja··on Ask HN: Are there any 4K “dumb” televisions?
A Gigabyte FO48U (48" OLED, same LG panel as the C1) goes for around $1500
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