2.0 - Introduction to Linux

 

What is Linux ?
- Linux is a free and open source operating system that is causing a revolution in the computer world
- Originally created by Linus Torvalds with the assistance of developers called community
- This operating system in only a few short years is beginning to dominate markets worldwide
- Today right from hand-held devices (ex: Android) to high end systems (ex: Stock exchange servers) use Linux

Why use Linux?
- Free & Open Source : No need to pay
- Reliability : 24x7x365 systems
- Secure : Monolithic Kernel design
- Scalability : From phones to super-computers

Linux: Properties
- What has made Linux so popular to scale from mobile devices to powering 90% of world’s super computer? Here are the key properties of Linux.
- Multitasking: Ability to handle multiple tasks across single / multiple processors
- Multi-user: Have got users with different level of privileges for secured access
- Protected Memory: Clear distinction called ‘user-space’ and ‘kernel’ space thereby having protected memory access. This makes Linux Super secure comparing with other operating systems
- Hierarchical File System: Well organized file system that handles various types of files. This also makes handling various inputs very simple

Directory structure

/boot/  -  Static files for boot loader
/dev/   -  Device files
/bin/   -  Essential user command binaries
/etc/   -  Host specific system configuration
/home/  -  User home directories
/lib/   -  Essentilal shared libraries and kernal modules
/media/ -  Mount point for removable media
/mnt/   -  Mount point for temporarily mounted file systems
/opt/   -  Add-on application software package
/sbin/  -  User specific system binaries
/tmp/   -  Temporary files
/usr/   -  Multi-user utilities and applications
/var/   -  Variable file (logs)
/root/  -  Home directory for root user
/proc/  -  Virtual file system documenting kernel and process status

...