Linux
Essential Linux server administration guides and command-line tutorials.
- watch Command on Linux: Monitor df, ss, and Logs Every Few Seconds
- umask on Linux: Default File Permissions Explained (022, 027, sftp)
- dmesg on Linux: Read Kernel Logs (Hardware, OOM, USB, Disk Errors)
- tcpdump on Linux: Capture Packets by Port and Host (Filters & pcap)