ACT Sofia traning center

Shell Programming for System Administrators

Prerequisites
To succeed fully in this course, students should be able to:

Use basic UNIX commands, such as rm, cp, man, more, mkdir, ps, and chmod
Create and edit text files in vi or a text editor

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Course Content
Module 1 - UNIX Shells and Shell Scripts

Describe the role of shells in the UNIX environment
Describe the standard shells
Define the components of a shell script
Write a simple shell script

Module 2 - Writing and Debugging Scripts

Start a script with #!
Put comments in a script
Change permissions on a script
Execute a script
Debug a script

Module 3 - The Shell Environment

Use Bourne and Korn shell variables
Assign values to shell variables
Display the value of shell variables
Make variables available to subprocesses using the export statement
Display the value of environment variables
Unset shell and environment variables
Customize the user environment using the .profile file
Perform arithmetic operations
Create and use aliases
Display aliases and the values assigned to them
Define the built-in aliases
Customize the Bourne and Korn shell environments
Use the tilde expansion and command substitution features of the Korn shell

Module 4 - Regular Expressions and the grep Command

Use and describe regular expressions
Describe the grep command
Use the grep command to find patterns in a file
Use the regular expression characters with the grep command

Module 5 - The sed Editor

Use the sed editor to perform noninteractive editing tasks
Use regular expression characters with the sed command

Module 6 - The nawk Programming Language

Use nawk commands from the command line
Write simple nawk programs to generate data reports from text files
Write simple nawk programs to generate numeric and text reports from text files

Module 7 - Conditionals

Use the exit status of a command as conditional control
Use the “if” statement to test a condition
Pass values using command-line arguments (positional parameters) into a script
Create USAGE messages
Place parameters on the command line
Use conditional if, then, elif, else, and fi constructs
Use exit, let, and test statements ([[ ]], ” “)
Apply the &&, ||, and ! Boolean logic operators
Use the case statement

Module 8 - Interactive Scripts

Use the print and echo commands to display text
Use the read command to interactively assign data to a shell variable
Read user input into one or more variables, using one read statement
Use special characters, with print and echo, to make the displayed text more user friendly
Create a “here” document
Use file descriptors to read from and write to multiple files

Module 9 - Loops

Write scripts that use for, while, and until loops
Write a script using the select statement
Describe when to use loops within a script
Generate argument lists using command, variable, and file-name substitution

Module 10 - Advanced Variables, Parameters, and Argument Lists

Declare strings, integers, and array variables
Manipulate string variables
Change the values of the positional parameters using the set statement within a script
Use Korn shell arrays
Set default values for parameters
Use the Korn shell built-in let, print, set, and typeset statements

Module 11 - Functions

Create user-defined functions in a shell script
Create, invoke, and display functions from the command line
Pass arguments into a function
Call functions from special (function) files that are saved in one or more function directories
Describe where functions are available for use

Module 12 - Traps

Describe how the trap statement works
Include trap statements in a script
Use the trap statement to catch signals and handle errors