Brief overview about linux operating system

• Brief Introduction about Linux Operating Systems

• History of Linux Operating System

• Linux Distributions

• Linux Kernel Architecture Fundamentals

Linux Basic Commands

• uname - print system information

• arch - print machine hardware architecture name

• hostid - prints numeric identifier of current host

• hostname - print local host name

• free - display amount free and used memory in the system

• id - prints real and effective user id and group id

• logname - prints the user's login name

• whoami - prints the effect user id

• users - prints the currently logged in users information

• groups - print the groups that a user is in

• who - show who is logged in

• date - print or set the system date and time

• cal - displays a calendar

• printenv - print all or part of environment variables

• echo - writes argument into standard output

• cd - change the current working directory

• mkdir - make directories

• df - reports file system disk space usage

• du - estimates the file space usage

• which - shows full path of the command

• whatis - displays one line manual page descriptions

• whereis - locate the binary, source, and manual page files for a command

• sum - checksum and count the blocks in a file

• cksum - checksum and count the bytes in a file

• md5sum - compute and check MD5 message digest

• base64 - base64 encode/decode data and print to standard output

• sha1sum - compute and check SHA1 message digest

• sha256sum - compute and check SHA256 message digest

• sha384sum - compute and check SHA384 message digest

• sha512sum - compute and check SHA512 message digest

File and Directory Management Commands

• mkdir - make directories

• rmdir - remove empty directories

• rm - remove files or directories

• rm - remove files or directories

• reverse search of commands instead of typing in command terminal

• cd - change the working directory

• basename, dirname - strip directory and suffix from filenames

• cp - copy files and directories

• mv — move files

• ln - make links between files

• unlink - call the unlink function to remove the specified file

• stat, fstat, lstat, fstatat - get file status

• od - dump files in octal and other formats

• cat - concatenate files and print on the standard output

• tac - concatenate and print files in reverse

• nl - number lines of files

• head - output the first part of files

• tail - output the last part of files

• more - file perusal filter for crt viewing

• less - opposite of more

• grep — search a file for a pattern

• tr - translate or delete characters

• cut - remove sections from each line of files

Process Management Commands

• ps - report a snapshot of the current processes.

• pstree - display a tree of processes

• uptime - displays system running time

• kill - sends a signal to the process

• nice - run a program with modified scheduling priority

• top - display Linux processes

• pmap - report memory map of a process

• slabtop - display kernel slab cache information in real time

• tload - graphic representation of system load average

• lsof - list open files

• proc - process information pseudo-filesystem

• procinfo - Shows System Statistics from /proc Filesystem

Linux Root File System and Hierarchy

• /bin

• /boot

• /dev

• /sbin

• /usr

• /var

• /proc

• /sys

• /lib

Linux Shell Scripting Basics

• Brief Introduction

• Simple Shell Script

• Shell Variables

• Array variables

• Arithmetic Operators

• If - Decision Making

• Relational Operators

• Boolean Operators

• String Operators

• File test operator

• Control Loop ( While, For, Until )