Welcome to Linux Community

A free Unix-type operating system developed under the GNU General Public License. ● Open source ● Popular ● Support most of the platforms available What is GNU/Linux?

– Multics, AT&T Bell Lab, GE, MIT – 1969, UNIX, Ken Thompson, Dennis Ritchie – 1973, Rewrite UNIX with C – Berkeley UNIX(BSD UNIX) – Commercial products ● SunOS, Solaris, HP-UX, AIX, SCO UNIX A Short History of UNIX

A Short History of Linux

A Short History of Linux(2)

Is Linux difficult ? This may be true. But the real question is: do you really want to learn it?

What are the benefits of Linux? Linux can give you: A modern, very stable, multi-user, multitasking environment. Advanced graphical user interface. Linux uses a standard, network- transparent X-windowing system with a "window manager" (typically KDE or GNOME but several are available). The graphical desktop under Linux can be made to look like MS Windows (or probably ANY other graphical user interface of your choice).

Dozens of excellent, free, general-interest desktop applications. These include a range of web browsers, programs, word processors, spreadsheets, bitmap and vector graphics editing programs, file managers, audio players, CD writers, some good games, typing tutor, etc. Freedom from viruses. Linux has no viruses because it is too secure an operating system for the viruses to spread with any degree of efficiency.

Linux is quite positively here-to-stay because of its open-source nature (Linux cannot possibly be put out-of-business). It is a standard selected for countless projects that are not going to go away, and some of them are quite "mission-critical." Try the International Space Station, for which Linux is the operating system (

In a nutshell, the GNU General Public Licence (GPL) allows anybody to: ➢ use the software at no charge, without any limitations, ➢ copy, and distribute or sell unmodified copies of the software in the source or binary form, ➢ use the software with propriatory (e.g., your own) modifications, free of charge, as long as you do not distribute or sell the modified version, ➢ modify, and distribute or sell a modified version of the software as long as the source code is included and licenced on the same terms as the original you received (the GPL), ➢ sell support for the software, without any limitations.

What the GPL license *does not* allow code recipients to do is to take somebody elses software licenced under GPL, modify the software, and then distrubute a this modified version of the software under a propriatory licence. Speaking plainly, the GPL licence just forbids stealing existing (somebody else's) software for incorporation into a closed, commercial-only product.

Things go wrong on many MS Windows NT machines every day, and there are no damages awarded by courts. Read your MS Windows license agreement to find out that there is no guarantee whatsoever that ANYTHING will work. Trying to sue would be a waste of your money. I need warranty and security. With commercial software, I can sue if things go wrong.

● A Linux distribution, often simply distribution or distro, is a member of the Linux family of Unix-like computer operating systems. ● Distros mainly based on ‘Look and Feel’ and Applications Linux Distros ● ： Distros: ● Red Hat Fedora, Debain, SuSe,Ubuntu, Gentoo

● Windows uses letters of the alphabet to represent different devices and different hard disk partitions. Under Windows, you need to know what volume (C:, D:,...) a file resides on to select it, the file's physical location is part of it's name. ● In Linux all directories are attached to the root directory, which is identified by a forward- slash, "/". - root. ● For example, below are some second-level directories: File System

/bin System binaries, including the command shell /boot Boot-up routines /dev Device files for all your peripherals /etc System configuration files /home User directories /lib Shared libraries and modules /lost+found Lost-cluster files, recovered from a disk-check /mnt Mounted file-systems /opt Optional software /proc Kernel-processes pseudo file-system /root Administrator’s home directory /sbin System administration binaries /usr User-oriented software /var Various other files: mail, spooling and logging

● man ● info ● command –help ● Forums. Linux Help

– The “-k” option ● man –k print – Manual pages are divided in 8 sections: User commands System calls Libc calls Devices File formats and protocols Games Conventions, macro packages and so forth System administation – To select correct section, add section number: ● man 1 passwd, man 5 passwd man command

info command ● A program for reading documentation, sometimes a replacement for manual pages ● Example : info ls

Links : Download Source Code from: Books: Unix User Guide – Rebecca Thomas Your UNIX: The Ultimate Guide-Sumitabha Das

Thank you