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Cryptocurrency Ethereum Mastering Development

Which operations can change ethereum address balance?

I am writing a program that would monitor changes in balance of a set of ethereum addresses. I did the same for UTXO based coins, and the logic was pretty simple. All of the changes were directly recorded in blocks. But ethereum appears to be more complicated. Which operations I have to monitor to be […]

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Linux Mastering Development

No internet on Linux Mint 19.3 Cinnamon

Well, in Network Settings it says that it’s wired and connected, but when I try to look up something on Chrome the error message is DNS_PROBE_FINISHED_NO_INTERNET. On my phone it says ‘Connected, no internet’. What can I do?

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Linux Mastering Development

apt not installing applications correctly – missing executable

I’m on Debian 10, KDE. I’m installing a package with apt and no errors are shown. However when I try to execute the program I get an error re missing executable. E.g. >>> sudo apt install knights # …. installs knights without error >>> knights Unknown command When trying to execute knights via the KDE […]

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Linux Mastering Development

bash read netcat status in pipe then exit

I don’t understand how to properly setup a data transmission between two host with unstable ethernet connection. This is my /simple/bash/script.sh #!/bin/bash while [ true ]; do cat /dev/virtual | nc -v 192.168.1.1 5005 || echo “nc failed” && exit sleep 5s done exit If I manually start it and on the destination netcat isn’t […]

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Linux Mastering Development

How can I verify a LUKS master key?

I have a master key for an encrypted partition on a machine that I have SSH + root access to. I don’t have access to any of the passphrases associated with the partition. Is there a way that I can verify that the master key is valid for that partition? I can’t unmount the partition […]

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Linux Mastering Development

SSH X11 forwarding – Authentication issue only with specific application

I have two raspis and connect from one to the other using SSH and X11 forwarding, ssh pi@[pi’s IP] -X -v. Displaying the remote GUI using X11 forwarding works fine for many applications. However, for one application it’s not working. It’s the demo application of the ADI tof sdk. When I start this in my […]

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Linux Mastering Development

Adding a key with “ssh-add” works but passing it with “-i” doesn’t

I have a case like follows: ssh -J${some-jump-host} -i some-key.pem opc@${some-ip} which does not ask for the key password for some-key.pem but directly fail as it is not authenticated. However, if I do: ssh-add -K some-key.pem ssh -J${some-jump-host} opc@${some-ip} this asks the password when adding the key, then it works. I have $ cat ~/.ssh/config […]

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Linux Mastering Development

sed command not identifying exact word in a variable

I am trying to replace a word irrespective of it’s case in a file using sed command as below: sed -ie s/$tbl/$third_ele/gI $sql_file where $tbl contains word S_ASSET and $third_ele contains table_01. This breaks when the file contains word S_ASSET_XA, the script replaces S_ASSET_XA to table_01_XA which i don’t want. I need to match it […]

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Linux Mastering Development

Send null byte in unix pipe

I am trying to redirect python generated input to ELF 64-bit executable in bash 5.0.3. I am getting: > ./bf <<< $(python2 -c “print(‘c’*6+b’\x00’+’c’*6)”) bash: warning: command substitution: ignored null byte in input Enter password: Password didn’t match input: cccccccccccc How can I allow a null byte in the input?

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Linux Mastering Development

‘exec’ option ignored in fstab for sshfs, need to specify to ‘mount’ on command-line?

I’m using sshfs in my fstab to mount a filesystem in Ubuntu 18.04.04 LTS: sshfs#dave@myservergoeshere.com:/remote-dir /mnt/local-mnt fuse rw,exec,user,allow_other,noauto,reconnect,ServerAliveInterval=15,ServerAliveCountMax=3 0 0 It mounts fine, but if I try to execute anything in the path I get: ./some-executable: Permission denied. The file has execute permissions (and works fine if I am actually ssh’d into the system). If […]