- Everything is a file: – UNIX system has many powerful utilities designed to create and manipulate files. The UNIX security model is based on the security of files. By treating everything as a file, you can secure access to hardware in the same way as you secure access to a document.
- Configuration data stored in text: – Storing configuration in the text allows an administrator to move a configuration from one machine to another easily, provide the ability to roll back a system configuration to a particular date and time.
- Small, Single-Purpose Programs: – UNIX provides many utilities.
- Avoid captive user interfaces
- Ability to chain programs together to perform complex tasks:- A core design feature of UNIX is that the output of one program can be the input for another. This gives the user the flexibility to combine many small programs together to perform a larger, more complex task.
GNU Project/ FSF
- GNU project started in 1984
- Goal: Create ‘free’ UNIX clone
- By 1990, nearly all required user space applications created.
Example:-gcc, emacs, etc.
- Free Software Foundation
- Non-Profit organization that manages the GNU project.
GPL – GNU (General Public License)
- primary license for open source software
- encourages free software
- All enhancements and changes to GPL software must also be GPL
- Often called ‘copy left’ (All rights reversed)
- LINUS TORVALDS
- Finnish college student in 1991
- Created Linux Kernel
- When Linux Kernel combined with GNU applications, complete free UNIX like OS was developed.
- Fresh implementation of UNIX APIs
- Open source development model
- Supports a wide variety of hardware
- Supports many networking protocols and Configurations
- Fully supported.
- Linux is a UNIX like OS: Linux is similar to UNIX as the various UNIX versions are to each other.
- Multi-User and Multi-tasking: Linux is a multi-user and multi-tasking operating system. That means that more than one person can be logged on to the same Linux computer at the same time. The same user could even be logged into their account from two or more terminals at the same time; Linux is also Multi-Tasking. A user can have more than one program executing at the same time.
- Wide hardware support: Red Hat Linux support most pieces modern x86 compatible PC hardware.
- Fully Supported: Red Hat Linux is a fully supported distribution Red Hat Inc. provides many support programs for the smallest to the largest companies.