Linux Bash Shell Programming

Session 7: LOOP CONSTRUCTS

• The while loop
• The until loop
• The while true and until false loops
• The for loop
• Loop control commands
• Exercises: Enhance the previously written scripts with loop constructs

Session 8: MULTI-BRANCH DECISIONS

• The case statement
• Patterns and actions
• Menu driven applications
• Exercise: Develop and write a menu system

Session 9: FUNCTIONS

• What is a function?
• Function syntax
• Exercises: Create and use functions

Session 10: INTERRUPT HANDLING

• Interrupt signals
• The trap command
• Abnormal termination of scripts
• Exercise: Adding traps to the menu script

Session 11: ADDITIONAL FEATURES

• The exec command
• The includes notation
• Arrays
• Here Documents
• Exercise: Enhance scripts

Session 12: BACKUP AND RESTORE UTILITIES

• The tar command
• Compression utilities gzip, bzip2, zip and compress
• Exercise: Backing up and restoring files using tar
• Exercises: Compressing files

Session 13: BACKGROUND JOB SCHEDULING

• Scheduling jobs with the cron command
• Scheduling jobs with the at command
• Exercises: Running background jobs

Session 14: COMMANDS FOR COMPARING FILES

• Compare two files with the cmp command
• Compare two files with the comm command
• Compare two files with the diff and sdiff commands
• Compare large files with the bdiff command
• Exercises: Identifying file differences

Session 15: SPLITTING FILES

• The split and csplit commands
• Exercises: Splitting files

Session 16: IDENTIFYING AND TRANSLATING CHARACTERS

• od - octal dump
• Use cat to display non-printing characters
• The expand and unexpand commands to convert between tab and space characters
• The tr command for character translation
• Exercises: Translating characters with tr

Session 17: REGULAR EXPRESSION NOTATION REVIEW

• Standard regular expressions
• Extended regular expressions

Session 18 THE STREAM EDITOR - sed

• sed command line syntax
• sed command processing
• Pattern space
• sed addresses
• sed commands
• Hold and get functions
• Advanced flow control
• Exercises: Text processing with sed

Session 19: INTRODUCTION TO THE PATTERN SCANNING UTILITY - awk

• Introduction and command line syntax
• The awk program structure
• Operators
• Simple patterns
• Extended patterns
• Special patterns (BEGIN and END)
• Program variables: Built-in variables, User defined variables, Arrays
• Mathematical operators
• Displaying output with print and printf
• Exercises: Create awk scripts to extract selected data from a file and generate reports

Session 20: awk PROGRAM CONTROL STRUCTURES

• Program control structures
• The if construct
• The while and do ... while constructs
• The basic for construct
• Associative array handling
• Functions: Mathematical and string functions, The system function, The getline function, User defined functions
• Exercises: Create an awk script using an program control structures and arrays

Session 21: awk DEBUGGING AWK SCRIPTS

• Responding to Syntax errors
• Responding to Logical errors

Session 22: MISCELLANEOUS TOOLS

• bc (calculator)
• fuser (testing for files in use)
• getops (checking options passed to shell scripts)
• printf (formatting screen output)
• logger (script logging)
• xargs (generating arguments for a command)
• eval (re-evaluating variables)
• Exercises: Using tools within a shell script