Linux command-line notes and practical examples for everyday administration, troubleshooting, and shell work.
su starts a shell as another user. It is commonly used to switch to the root account or to test commands under a different account. Switch to another user su – username The hyphen starts a login shell, so the target user’s environment is loaded. Switch to root su – This normally asks for the … Read more
bzip2 is a command-line tool for compressing files on Linux. It usually creates files with a .bz2 extension. Compress a file This creates filename.txt.bz2 and removes the original file by default. Decompress a file To keep the original file while compressing or decompressing, use -k.
adjtimex exposes low-level Linux kernel timekeeping parameters. It is mainly useful for diagnostics, experimentation, and older time-synchronisation workflows; most systems should use a supported time service such as chrony or systemd-timesyncd for normal clock synchronisation. Inspect current parameters adjtimex -p This displays kernel time variables such as tick and frequency adjustments. Use caution when changing … Read more
A practical rpm reference for querying RPM packages, with guidance on using dnf for normal dependency-aware package management.
lspci shows PCI buses and devices detected by Linux. It is useful for identifying network adapters, storage controllers, graphics devices, USB controllers, and other PCI hardware. Common commands lspci lspci -v lspci -vv lspci -nn lspci -k -v and -vv show increasing detail. -nn includes numeric vendor and device IDs. -k shows the kernel driver … Read more
dos2unix converts text files from Windows line endings to Unix/Linux line endings. This is useful when shell scripts edited on Windows fail with strange errors. Convert a file After converting, make sure the script has execute permission if you want to run it directly. Check file type If the file shows CRLF line terminators, dos2unix … Read more
Modern Linux commands for inspecting PCI, USB, storage, CPU, firmware, and driver information.
When you forget a command’s syntax or want to discover the right tool, Linux already includes several built-in help systems. man man command Use man for the full manual page. Inside the viewer, press / to search, n for the next match, and q to quit. –help and shell help command –help help cd –help … Read more
Practical building blocks for safer and more maintainable Bash scripts.
A beginner-friendly Bash overview with basic commands, variables and a simple script.