All Notes - Page 11 of 14

eject — Eject the removable media

October 15, 2026July 6, 2005 by Gaurav Masand

Linux is included in 11th std Computer Science syllabus in Tamil Nadu.
Linux Users Groups should help the Teachers and Students to understand
the Linux and FOSS concepts.

One Day One Command
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eject — Eject the removable media

Summary:

Eject allows removable media (like CD-ROM, Floppy, Tape, JAZ, ZIP) to

be ejected under software control. The command can also control some

multi-disc CD-ROM changers, the auto-eject feature supported by some

devices, and close the disc tray of some CD-ROM drives.

Linux Malware and Adware: What Has Changed

October 15, 2026July 5, 2005 by Gaurav Masand

An updated perspective on malware, spyware, and adware on Linux, with practical security habits for modern systems.

su — Run a Shell as Another User

October 16, 2026July 5, 2005 by Gaurav Masand

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

Safely Allow Users to Run Administrative Commands

October 16, 2026July 5, 2005 by Gaurav Masand

If a user needs to run a small set of administrative commands, the preferred approach is usually a carefully scoped sudo rule rather than making arbitrary programs setuid root. Use sudo with least privilege Edit sudo policy with visudo or a file under /etc/sudoers.d/. Grant only the exact commands required, and avoid broad rules such … Read more

Safely Unmount a Busy CD or Removable Filesystem

October 16, 2026July 4, 2005 by Gaurav Masand

If umount reports that a CD, USB drive, or other removable filesystem is busy, first find out which process is still using the mount point. Killing processes blindly can cause data loss or interrupt unrelated work. Find what is using the mount fuser -vm /mount/point lsof +D /mount/point Close shells, file managers, editors, or applications … Read more

bzip2 — Compress and Decompress Files in Linux

October 14, 2026June 28, 2005 by Gaurav Masand

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: Inspect Linux Kernel Time Parameters

October 16, 2026June 28, 2005 by Gaurav Masand

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

rpm Package Manager: Practical Reference

October 16, 2026June 27, 2005 by Gaurav Masand

A practical rpm reference for querying RPM packages, with guidance on using dnf for normal dependency-aware package management.

lspci: List PCI Devices in Linux

October 16, 2026June 26, 2005 by Gaurav Masand

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

Increase Hard Drive Output: Legacy hdparm Note

October 14, 2026June 26, 2005 by Gaurav Masand

Legacy hard drive performance note with safer modern guidance.