Nothing Special   »   [go: up one dir, main page]
Scribd Logo
Upload

Welcome to Scribd!

  • 98 views

    Module 6

    Uploaded by

    Mihai S
    This document provides an introduction to shell scripting in Linux. It discusses that a shell script is a file containing shell commands that are executed sequentially to perform automation tasks. It describes different types of shells like sh, bash, ksh and csh. It also explains how to write basic shell scripts using commands like echo, create scripts using control structures like if-then and for loops, and take user input. The document concludes with discussing aliases and command history.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd

    Module 6

    Uploaded by

    Mihai S
    98 views15 pages
    This document provides an introduction to shell scripting in Linux. It discusses that a shell script is a file containing shell commands that are executed sequentially to perform automation tasks. It describes different types of shells like sh, bash, ksh and csh. It also explains how to write basic shell scripts using commands like echo, create scripts using control structures like if-then and for loops, and take user input. The document concludes with discussing aliases and command history.

    Original Description:

    Original Title

    Module-6

    Copyright

    © © All Rights Reserved

    Available Formats

    PDF, TXT or read online from Scribd

    Did you find this document useful?

    Is this content inappropriate?

    This document provides an introduction to shell scripting in Linux. It discusses that a shell script is a file containing shell commands that are executed sequentially to perform automation tasks. It describes different types of shells like sh, bash, ksh and csh. It also explains how to write basic shell scripts using commands like echo, create scripts using control structures like if-then and for loops, and take user input. The document concludes with discussing aliases and command history.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    98 views15 pages

    Module 6

    Uploaded by

    Mihai S
    This document provides an introduction to shell scripting in Linux. It discusses that a shell script is a file containing shell commands that are executed sequentially to perform automation tasks. It describes different types of shells like sh, bash, ksh and csh. It also explains how to write basic shell scripts using commands like echo, create scripts using control structures like if-then and for loops, and take user input. The document concludes with discussing aliases and command history.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    of 15

    Welcome To:

    Module 6

    Shell Scripting
    Linux Kernel
    • What is a Kernel?
    • Interface between hardware and Software

    Browser, sendmail
    Software
    GUI, bash, csh
    Operating System
    Program

    CPU, Memory, HD

    By: Imran Afzal


    Introduction to Shell

    • What is a Shell?
    • Its like a container
    • Interface between users and Kernel/OS
    • CLI is a Shell

    • Find your Shell


    • echo $0
    • Available Shells “cat /etc/shells”
    • Your Shell? /etc/passwd

    • Windows GUI is a shell


    • Linux KDE GUI is a shell
    • Linux sh, bash etc. is a shell
    By: Imran Afzal
    Types of Shell
    • sh
    • bash
    • ksh
    • csh

    Starting a Shell
    • Type shell name e.g. csh
    • Type exit to exit out of shell

    By: Imran Afzal


    Shell Scripting
    • What is a Shell Script?
    A shell script is an executable file containing multiple shell commands that are executed
    sequentially. The file can contain:

    • Shell (#!/bin/bash)
    • Comments (# comments)
    • Commands (echo, cp, grep etc.)
    • Statements (if, while, for etc.)

    • Shell script should have executable permissions (e.g. -rwx r-x r-x)
    • Shell script has to be called from absolute path (e.g /home/userdir/script.bash)
    • If called from current location then ./script.bash

    By: Imran Afzal


    Shell Script – Basic Scripts

    • Output to screen using “echo”

    • Creating tasks
    • Telling your id, current location, your files/directories, system info
    • Creating files or directories
    • Output to a file “>”

    • Filters/Text processors through scripts (cut, awk, grep, sort, uniq, wc)

    By: Imran Afzal


    Input and Output of Script
    • Create script to take input from the user

    read
    echo

    By: Imran Afzal


    if-then Scripts

    • If then statement

    If this happens = do this


    Otherwise = do that

    By: Imran Afzal


    For Loop Scripts

    • For loops

    Keep running until specified number of variable


    e.g: variable = 10 then run the script 10 times
    OR
    variable = green, blue, red (then run the
    script 3 times for each color.

    By: Imran Afzal


    do-while Scripts

    • do while

    The while statement continually executes a block of statements while a


    particular condition is true or met

    e.g: Run a script until 2pm

    while [ condition ]
    do
    command1
    command2
    commandN
    done

    By: Imran Afzal


    Case Statement Scripts

    • Case

    If option a is selected = do this


    If option b is selected = do this
    If option c is selected = do this.

    By: Imran Afzal


    Check Other Servers Connectivity

    • A script to check the status of remote hosts

    By: Imran Afzal


    Aliases
    • Aliases is a very popular command that is used to cut down on lengthy and
    repetitive commands

    alias ls="ls -al“


    alias pl=“pwd; ls”
    alias tell=“whoami; hostname; pwd”
    alias dir="ls -l | grep ^d"
    alias lmar=“ls –l | grep Mar”
    alias wpa= "chmod a+w"
    alias d="df -h | awk '{print \$6}' | cut -c1-4"

    By: Imran Afzal


    Creating User or Global Aliases
    • User = Applies only to a specific user profile
    • Global = Applies to everyone who has account on the system

    • User = /home/user/.bashrc
    • Global = /etc/bashrc

    alias hh=“hostname”

    By: Imran Afzal


    Shell History

    • Command “history”

    By: Imran Afzal

    You might also like