ENGINEERING COMPUTING CENTER LINUX workshop

WHAT WILL BE COVERED UNIX/Linux Overview Red Hat Enterprise Linux How to Login Password Reset Applications Command Line Change Password Shell Commands and Create Text Files Linux File-system Hierarchy File Permissions Remote Access & File Transfer Security & ECC Policies

UNIX overview UNIX was developed in 1969 at Bell Labs. Originally used as a workbench for programmers to develop new software for testing. Main Functions of UNIX: - High performance - Resource Sharing - Multi-User Access - Programming and Software Development

Flavors of unix

UNIX distributions Open Source: Linux, Minix, FreeBSD, OpenSolaris Open & Closed Source: Android Closed Source: MacOS X, Solaris, AIX, HP-UX

LINUX Linus Torvalds developed the Linux kernel in 1991. Collaborated with the GNU Project in 1992, to create the first free operating system for the public. Many distrubutions of Linux include Debian, Fedora, Mandriva, SUSE, Slackware, and Android Most distributions are free for use, some are NOT

Advantages of a Linux OS? Hardware/Software High Compatibility Resource Allocation/Sharing Flexibility Security Very few Viruses Encryption Dynamic Firewall Choice Complete Control Open Source Software Scripting and Automation Experimentation

RED HAT ENTERPRISE LINUX 6 Originally Released in 2003 Mainly used as enterprise level server OS Trademark and Support are NOT free CentOS and Scientific Linux are free rebuilds

Centos 6 http://www.centos.org/ A free, community supported enterprise OS. Exact replica of RedHat Enterprise Linux

HOW TO LOGIN OPEN X-WIN 32 FROM START MENU CONFIGURE X-WIN 32: - New Connection “Manual” Choose ‘XDMCP’ ‘General’ tab Connection Name: tuxedo XDMCP mode: Query HOST: tuxedo.egr.uh.edu Hit ‘Save’ Hit ‘Launch’ USE ECC UNIX ACCOUNT TO LOGIN

RESET PASSWORD (online) GO TO: http://www.uh.edu/infotech/ Click “Password Reset” Choose the box “I need to reset a password that is not listed here” Enter security information Click “Reset”

NAGIVATE THE GUI (GRAPHICAL USER INTERFACE) Applications - accessories - word processing - system tools - command line (terminal) Places - Home folder - subdirectories - search for files System - Preferences - Administration Utilities - System Documentation

APPLICATIONS Firefox Libre Office Terminal Text Editors - web browser - Open source version of Microsoft Word, Excel, Powerpoint Terminal - command line shell prompt - faster than GUI Text Editors - EMACS - VI/ VIM/ NANO (command line)

Class software location Located: /usr/local MATLAB, Abacus, Fluent, Cadence, Comsol, etc…

ACCESS THE COMMAND LINE PROMPT Applications  System tools  Terminal Fully text based command prompt Shell prompt [ username@<hostname> <current working directory>] $

USING SIMPLE SHELL COMMANDS Navigation: ls – list directory contents ls –l - view files and permissions pwd – print, current working directory cd – change directory cd <directory path> Ex. cd /home/user Copying, Moving, and Deleting cp – copy files and directories cp <file source> <file destination> mv – move or rename file mv <file source> <file destination> touch – make basic text files touch <file name> mkdir – create a directory mkdir <directory file path> rm – delete file or directory (can be destructive) rm <file path> rmdir – delete directory (empty directory) rmdir <file path>

SHELL COMMANDS (continued) Search commands: find – search for files Find <sourse directory> -name <name of file or directory> -print Documentation: man – manual pages man <command or application> Change File Permissions: chown – change file owner and group chown owner:group <file path> chgrp <groupname> <file path> chmod – change file mode and permissions chmod <permission number> <filepath> Read = 4 Write =2 Execute = 1 System commands: top – shows current processes that are running df –h: show the file system disk space usage w – shows who is logged on to the system uptime – see date, load average, and # of users uname –a : to see current OS version and computer hostname Network Statistics Ifconfig – network card information netstat –rn: see IP routing information

Change password (command Line) New password format: mmddyy<last initial>! Type command in prompt to reset: yppasswd Will prompt for old password Password Rules: Minimum 8 characters. At lease one Capital Letter At least one Special char @#&%!

Create & EDITING TEXT FILES VIM vim <edit file name or new file create> NANO Nano <file> EMACS GUI text editor

Linux File-system Hierarchy

FILE PERMISSIONS drwxrwxrwx First character: rwx permissions: d = directory (blue) l = symbolic link (cyan) ‘-’ = a file (white) rwx permissions: R = read W = write X = execute First set: owner Second set: group Third set: everyone

REMOTE ACCESS Ssh – Secure Shell client A program used for “shell” access to a remote system. Login using UNIX/Linux terminal (shell), or through “PUTTY” Use ECC UNIX account info to login PUTTY (for Windows Use) - free application - allows shell logins from a windows desktop

Remote access (cont) SSH from PUTTY: Open PUTTY app from Windows Type the hostname or IP of destination Port is always 22 Enter ECC-UNIX user ID, and password If successful, user command prompt will be shown SSH from another terminal (shell): Type command: ssh <username>@<hostname>

file Transfer WinSCP: Transfer files from Windows to Linux and vice versa Installation located in “software download” on Access UH Login: - Open WinSCP program - Enter user credentials, click login

SECURTIY & ECC POLICIES ECC website http://ecc.egr.uh.edu/engineering- computing-center-policies ECC Usage Policy http://ecc.egr.uh.edu/sites/ecc.egr.uh.e du/files/files/cce_policy_computing.pdf

Security DO NOT, give anyone your password DO NOT, let anyone use your ECC-UNIX account All activity is being tracked and logged, including command history. Report any suspicious activity to either Kiet Luong or Zain Marvi Kiet Luong Zain Marvi Engineering IT Director System Administrator 1 Information Security Officer Email: zhmarvi@central.uh.edu Email: KDLuong@Central.UH.EDU