Shell Programming (D85153)

Unix Shells

• Describe the role of shells in the UNIX environment
• Describe the various UNIX/Oracle Solaris shells

Shell Scripting

• Describe the structure of a shell script
• Create a simple shell script
• Implement the various debugging options in a shell script

Shell Environment

• Explain the role of startup scripts in initializing the shell environment
• Describe the various types of shell variables
• Explain command line parsing in a shell environment

Pattern Matching

• Describe the grep command
• Explain the role of regular expressions in pattern matching

The sed Editor

• Describe the sed editor
• Perform non-interactive editing tasks by using the sed editor

The nawk Programming Language

• Describe nawk as a programming language
• Display output by using the print statement
• Perform pattern matching by using regular expressions
• Use the nawk built-in and user-defined variables

Interactive Scripts

• Display output by using the print and echo statements
• Accept user input by using the read statement
• Describe the role of file descriptors in file input and output

Variables and Positional Parameters

• Describe the various types of scripting variables
• Define positional parameters for accepting user input

Conditionals

• Describe the role of the if statement in testing conditions
• Describe the syntaxes for the if/then/else and if/then/elif/else statements
• Choose from alternatives by using the case statement
• Perform numeric and string comparisons
• Compare data by using the &&, ||, and ! Boolean operators
• Distinguish between the exit status and the exit statement

Loops

• Describe the for, while, and until looping constructs
• Create menus by using the select looping statement
• Provide variable number of arguments to the script by using the shift statement
• Describe the role of the getopts statement in parsing script options

Functions

• Create user-defined functions in a shell script
• Use the typeset and unset statements in a function
• Autoload a function file into a shell script

Traps

• Describe the role of shell signals in interprocess communication
• Catch signals and user errors with the trap statement