Lamp

FOSS / LAMP Session - I

Revathi J Bharathidasan University Technology Park (BUTP) Bharathidasan University

Web • The WWW may seem like magic, until we understand how it works • The web is usually accessed through a browser (Netscape, Mozilla & Internet Explorer, Opera, links – text based etc)

How it works? • Type a URL into the location box, the browser makes a network connection to the server. • The URL name maps to an Internet address. • The browser connects to URL using port 80.

How the web works www.example.com N Disk Internet/ Network Data base Client

Server

•Render HTML Images, etc. •Execute JavaScript •Execute Java applets •Send data to server using CGI protocol

•Serve up content • HTML •Images •Documents, etc. •Process data received from client

Serving Up Static Data Server www.example.com

Request from Client

Disk



Content sent to client

No processing of text file

/var/www/html/ index.html

Serving Up Dynamic Data Server www.example.com

Request from Client

Disk

#1 /usr/bin/perl

Content sent to client Outputs HTML Perl

Executes a.cgi

/var/www/cgi-bin/ a.cgi

Serving Up Embedded data Server www.example.com

Request from Client

Disk



Content sent to client

Processor •mod_perl •PHP

Processes embedded HTML

/var/www/html/ a.html

Open Source Definition • Technical definition:  Source code is available to users

• Functional definition:

Usually free or cheap to acquire and use Primarily developed by volunteers Anyone can modify and customize Users have direct input into development

FLOSS

(Free/Libre & Open Source Software) • It is generic name of “Free Software” and “Open Source Software” • Open Source Software is named by Eric S. Raymond (ESR), Larry M. Augustin & others

Brief History of FLOSS 1984: 1985: 1991: 1998: 1999 :

GNU Project started Free Software Foundation was founded Linux development started Open Source Software Movement More & more software Apache, Mozilla, MySQL, PostgreSQL, PHP, Perl, Python, Ruby … 200x: Got attention by Governments

GNU Project (1) • Richard M. Stallman (RMS) started the Project • Goal: UNIX compatible replacement of Free (Free as in Freedom) Operating System • Software from GNU: - GCC (GNU Compiler Collection) - GNU Debugger - GNU Binutils - BASH …

GNU - General Public License (GPL) • Most popular open source license • Most widely used • 85% of open source software • Activities started with the first GNU Project(1)

GNU’s GPL – A Big List • Operating systems: Linux, Solaris • Web & email servers: Apache and Sendmail/Postfix/Qmail • Web & db languages: PHP/Perl and MySQL/PostgreSQL • Web content management: Drupal, Plone, Bricolage • Virus & spam protection: ClamAV, SpamAssassin • Desktop apps: Open Office, Mozilla, gAIM • Security: GPG

What is Free Open Source Software (FOSS)? It’s a free Software! ….But What is “free” ?

“Free” for “Freedom” According to GNU, • Freedom to run the software for any purpose (freedom 0) • Freedom to modify, fix and customize (freedom 1) • Freedom to redistribute (freedom 2) • Freedom to improve program and release them in public (freedom 3) Note: Not all open source software is cost-free, and not all cost-free software is open source

Free/Open Source Software (FOSS) "How can anything be good if it is free (i.e. has no monetary value attached to it)?!!!“ Cost free or License Free?

Licenses – Contract/ Agreement between users and developers of the software

Patent protection to owners but allow others to learn from it Copy right Power to exclude

Proprietary Software Vs Open Source Software • Source code availability • Source code availability ▫ Source code not provided ▫ Source code to original product always provided ▫ Source code provide ▫ Licensee can modify or  may or may not include enhance source code (create permission to create “derivative works”) modifications & enhance• Restrictions on distribution ments ▫ Licensees, subject to license • Restrictions on distribution terms, can: ▫ Licensee has no right to make and distribute share with those not copies of software defined as licensee users in build upon software to licenses create modifications or other works.

WHAT IS LAMP? LAMP stands for Linux, Apache, MySQL and PHP One of the fast growing ways to develop enterprise-level web applications All these packages are Open Source products So, you are basically free to use them as ‘U’ wish, the only limit is your own imagination

Linux • What is Linux? Open Source Operating System Freely distributed Based on Unix Being developed by programmers all over the world Very popular Unix brand

Linux • It was developed by Linus Benedict Torvalds • POSIX compatible kernel written from scratch • Together with other software, becomes Operating System • Such OS-es are called as ‘Distributions’ - Redhat, Fedora - Debian - SUSE - Ubando - Mandrake etc.

Where I can use Linux? • Server OS ▫ Linux is best suited for Server ▫ Characteristics : Stable, Robust, Secure & High performance ▫ Linux offer all characteristics + Open Source and free OS

• Stand alone OS on PC ▫ Word Processing, Graphics, Software development, internet, e-mail, chatting and personal database management system

In network environment • Linux Server with different Client OS

• Linux Server can act as Proxy/Mail/ WWW/Router Server

We can use Linux for • Web Server • Software Development Workstation • Workgroup Server • Data Center Server activities such as FTP, Telnet, SSH, Web, Mail, Proxy, Proxy Cache Appliance etc.

Graphical & Text Interfaces • Graphical ▫ Most modern desktop Linux systems provide a graphical user interface (GUI). ▫ Linux systems use the X window system to provide graphics. • Text ▫ Use Ctrl+Alt+F1 to switch to a text console — logging in works as it does in X. ▫ Use Ctrl+Alt+F2, Ctrl+Alt+F3, etc., to switch between virtual terminals — usually about 6 are provided. ▫ Use Ctrl+Alt+F7, or whatever is after the virtual terminals, to switch back to X.

Login & Logout • Login ▫ User needs an account to use a computer. ▫ The most common method used to authenticate a user is a “login” process, by entering a valid user name and password. • Logout ▫ To exit from the shell, use the exit command. ▫ Pressing Ctrl+d at the shell prompt will also quit the shell. ▫ After logging out, a new login prompt should be displayed.

Linux Command Line Command date cal clear

Purpose to display the system date and time to display the calendar clear the screen

Syntax $ date $ cal $ clear

who

to say who is on the system

$ who

whois

internet user name directory service locate a binary, source and manual page files to display short descriptions of the commands to display usage summary and argument list to display the documentation for a command it is similar to man, but often more indepth

$ whois [-h host] identifier

whereis whatis --help man info

$ whereis filename $ whatis $ --help $ man $ info

Linux Filesystem Hierarchical directory structure (tree) Every Linux filesystem has one and only one root – Hierarchical directory structure (tree) Root is always referred to as ‘/’ Every file and directory is located under this root directory

About Directories DIRECTORY /root, /home/<usrname> /boot /etc /usr /var /lost+found /media and /mnt

/dev /lib /opt /proc /tmp

TYPEOFINFORM ATIONSTORED User home directory kernel and boot loader S ystem nfigu n files M aintainco all binratio ary an d System binary files Server data related to recovery Foreign filesystem mount point /media for removable media and /mnt for non-removable media Device directory M aintain library files are pack M aintain So Sftw ystem andages kernel information Temporary files

Paths • Navigating the Linux filesystem is always done using paths • A path describes how to locate a particular file or directory • Two types – Complete or Absolute path: specifies all of the steps (directories) you need to traverse to get to the file or directory you want starting from the root – Relative path: specifies how to get from where you are now to the file or directory you want

Paths (cont.) /

home

exports

jack

data

• Complete path to my home directory: /home/jack • Relative Path from data: ../../home/jack OR ~

Examples of Relative Path • In each case the file being referenced is /usr/share/doc/HTML/index.html Current directory Relative pathname /usr/share/doc/HTML index.html /usr/share/doc HTML/index.html /usr/share doc/HTML/index.html /usr share/doc/HTML/ index.html / usr/share/doc/ HTML/index.html

Paths (cont.) • Separator between directories uses a forward slash: ‘/’ /home/jack

• To go up one directory use double dots: ‘..’ ../../home/jack

• To refer to your home directory use tilde: ~ ~jack

pwd & cd Command • pwd - Prints current working directory • (where we are right now) • Syntax : $ pwd • cd - Change current directory • Argument specifies path of • the directory you want to goto • Syntax : $ cd

Listing directory contents • $ ls : To list the content of the directory or a specified directory • $ ls -l : To list the long list details from the directory • $ ls -a : To list the hidden files and directories from the directory • $ ls -R : To list the recursive through subdirectories • $ ls -d : To list the directory names not their contents

Copying files and directories $ cp - to copy the source files and directories to the destination path. Note, the destination path must be a directory. Syntax: $ cp [option] <source file> <destination> $ cp [option] <multiple source file> <destination> Type of – option, i - interactive mode, ask before overwriting r - recursive mode, recursively copy an entire things f - force mode, force to copy a directory or file.

Moving files and Directories • The mv (move) command is used to move files and directories from source to destination. • The mv and cp functions are same, the only different is that cp results in matching identical files; with mv, the source disappears, leaving only the destination file(s). Syntax: $ mv <source> <destination>

Renaming Files and directories • rename command is used to rename the file and directorie. Syntax: $ rename $ rename

Creating files and directories • To create a empty file use the touch command. (Note, we can create multiple files in a single command) $ touch filename $ touch filename1 filename2 filename3 • To create a directory using mkdir command $ mkdir directoryname $ mkdir –p /directoryname/{dir1,dir2,dir3} ( create multiple subdirectory into /directoryname)

Removing files and directories • rm (remove) command is used to remove files and directories depending upon the option. Syntax: $ rm [option] file $ rmdir dir Type of – option, i - interactive mode, ask before overwriting r - recursive mode, recursively copy an entire things f - force mode, force to copy a directory or file.

History • The history command is used to list the entered commands with numbers. Syntax: $ history $ history –c $ !! $ !c -

//used to clear the history

to repeat the last command to repeat last command that start with ‘c’ $ !n - to repeat a command by its number in history output.

Use of Shortcut Key • The tab key can be used to complete command or a file name. • Press tab key to complete command line Example $his $history $ls -l tex $ls -l text.txt

Thank you