helpful_ubuntu_commands
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| Both sides previous revisionPrevious revisionNext revision | Previous revision | ||
| helpful_ubuntu_commands [2025/05/30 13:30] – mike | helpful_ubuntu_commands [2026/08/08 20:15] (current) – mike | ||
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| ====== Helpful Ubuntu/ | ====== Helpful Ubuntu/ | ||
| - | ---- | + | ==== Miscellaneous/ |
| === Disable Ubuntu Pro " | === Disable Ubuntu Pro " | ||
| - | <color red> | ||
| sudo pro config set apt_news=false | sudo pro config set apt_news=false | ||
| Line 10: | Line 10: | ||
| === List processes and the ports they are listening on === | === List processes and the ports they are listening on === | ||
| netstat -tulpn | grep LISTEN | netstat -tulpn | grep LISTEN | ||
| + | or | ||
| + | ss -tulpn | grep LISTEN | ||
| | | ||
| === Reload systemd manager configuration after changes made === | === Reload systemd manager configuration after changes made === | ||
| Line 22: | Line 24: | ||
| === Changing default editor for visudo === | === Changing default editor for visudo === | ||
| sudo update-alternatives --config editor | sudo update-alternatives --config editor | ||
| + | |||
| + | If visudo complains about a missing defaults.vim file, it can be fixed thusly: | ||
| + | sudo touch ~root/.exrc | ||
| | | ||
| === Disable GUI screen lock === | === Disable GUI screen lock === | ||
| Line 37: | Line 42: | ||
| === Determine the date the system was installed (not 100% reliable) === | === Determine the date the system was installed (not 100% reliable) === | ||
| tune2fs -l /dev/vda2 | grep ‘Filesystem created:’ (replace vda2 with device where root filesystem is located) | tune2fs -l /dev/vda2 | grep ‘Filesystem created:’ (replace vda2 with device where root filesystem is located) | ||
| - | | + | |
| + | === Copy an existing partition to a new partition === | ||
| + | sudo rsync -aAXv --info=progress2 --exclude='/ | ||
| === Finding largest files/ | === Finding largest files/ | ||
| du -a /dir/ | sort -n -r | head -n 20 (replace 20 with the # of lines you wish to have returned) | du -a /dir/ | sort -n -r | head -n 20 (replace 20 with the # of lines you wish to have returned) | ||
| + | === Find the oldest file in a directory (and it's subdirectories) === | ||
| + | find . -type f -printf '%T+ %p\n' | sort | head -n 1 | ||
| + | | ||
| + | === Finding files by file name (or file name portion) === | ||
| + | find . -iname < | ||
| + | | ||
| === Disable colors in the vi editor by default === | === Disable colors in the vi editor by default === | ||
| Create (or edit, if it exists) ~/.vimrc; into this file add the command syntax off, and save the file. | Create (or edit, if it exists) ~/.vimrc; into this file add the command syntax off, and save the file. | ||
| - | **Overwrite/ | ||
| - | |||
| - | dd if=/ | ||
| - | | ||
| === Find files consuming the root file system === | === Find files consuming the root file system === | ||
| mkdir / | mkdir / | ||
| Line 62: | Line 72: | ||
| OTA DVR recordings are saved as **.ts** files, which are not compatible with DaVinci Resolve (my video editor of choice). | OTA DVR recordings are saved as **.ts** files, which are not compatible with DaVinci Resolve (my video editor of choice). | ||
| ffmpeg -i < | ffmpeg -i < | ||
| + | |||
| + | **Overwrite/ | ||
| + | |||
| + | dd if=/ | ||
| + | |||
| + | ==== Ansible/ | ||
| | | ||
| === Generate password hashes (useful for Ansible playbooks amongst other things) === | === Generate password hashes (useful for Ansible playbooks amongst other things) === | ||
| mkpasswd --method=sha-512 | mkpasswd --method=sha-512 | ||
| + | |||
| + | === Generate random keys === | ||
| + | openssl rand -base64 48 | ||
| + | |||
| + | === Example of referencing an Ansible Vault === | ||
| + | ansible-playbook playbook.yml --vault-password-file ~/ | ||
| + | | ||
| + | ==== Extracting encrypted/ | ||
| + | .zip files that have been encrypted with AES-256 cannot be extracted via the default ' | ||
| + | apt update | ||
| + | apt install 7zip | ||
| + | Once installed, use the **7zz** command to extract the file (you will be prompted for the password used to initially encrypt the archive if one was used): | ||
| + | 7zz x < | ||
| + | |||
| ==== Cookbook for passing client IP address to systems behind a reverse proxy ==== | ==== Cookbook for passing client IP address to systems behind a reverse proxy ==== | ||
| === On the reverse proxy: === | === On the reverse proxy: === | ||
| Line 82: | Line 112: | ||
| Restart apache. | Restart apache. | ||
| - | === Create new GPT disk partition === | + | ==== Create new GPT disk partition |
| sudo into an elevated shell and then perform the following: | sudo into an elevated shell and then perform the following: | ||
| parted /dev/sdX (where X is the letter of the drive to be manipulated) | parted /dev/sdX (where X is the letter of the drive to be manipulated) | ||
| Line 93: | Line 123: | ||
| Then proceed to format the new drive, i.e. **mkfs -t ext4 /dev/sdb1** | Then proceed to format the new drive, i.e. **mkfs -t ext4 /dev/sdb1** | ||
| + | |||
| + | ==== Updating Network Settings ==== | ||
| === Changing the server' | === Changing the server' | ||
| Line 102: | Line 134: | ||
| hostnamectl set-hostname [new host name] | hostnamectl set-hostname [new host name] | ||
| | | ||
| + | === Changing the server' | ||
| + | Edit the **/ | ||
| + | Apply the changes with the **sudo netplan apply** command | ||
| + | === Disabling the local DNS resolver === | ||
| + | This becomes necessary if a DNS server is deployed on the local system, since it will conflict with the local resolver unless it is first disabled. | ||
| + | |||
| + | Edit **/ | ||
| + | DNSStubListener=no | ||
| + | |||
| + | Update the **resolv.conf** symlink: | ||
| + | sudo ln -sf / | ||
| + | | ||
| + | Restart **systemd-resolved**: | ||
| + | sudo systemctl restart systemd-resolved | ||
| + | | ||
| + | Validate that the system is no longer listening on port 53: | ||
| + | ss -tulpn | grep 53 | ||
| + | | ||
| + | ==== Creating SSH Keys ==== | ||
| + | To create an ed25519 key - | ||
| + | ssh-keygen -t ed25519 -C "< | ||
helpful_ubuntu_commands.1748637056.txt.gz · Last modified: by mike