POSIX shell programming

Prerequisites

• UNIX Fundamentals (HP 51434S) or equivalent experience
• Fundamental knowledge of programming

Audience

HP-UX and UNIX general users, system and network administrators, and software developers.

Ways to save

Benefits to you

• Understand POSIX shell programming and use it to save time with automated scripts
• Write efficient programs by understanding how shell scripts are processed
• Customize shell start-up files
• Easily control your administration tasks

Next Steps

Perl programming (H4311S)

Course outline

• Introduction to POSIX shell scripts
• What is a shell script?
• Script execution
• The subprocess environment
• Shell features
• Shell scripting
• Which shell?
• Recommended shell format
• Planning to write a shell script
• Portability issues
• Variables
• Variables
• Displaying and using variables
• Concatenation and substrings
• Other sources of data for variables
• User input
• Reading user input
• Positional parameters
• Creating positional parameters
• Conditional substitution
• External influences
• Designing program output
• Variable attributes
• Formatted data
• Cursor positioning and terminal echo
• Shell arithmetic
• Creating Integer-only Variables
• Base 10 and Others
• Working with arithmetic operators and data
• Branching and logic testing
• Logic testing
• Conditional operators
• Multi-way branching and the 'case' statement
• Shell patterns
• Basic expressions
• More complex patterns
• Pattern combinations
• Program loops
• The 'while' loop
• The 'until' loop
• The 'for' loop
• Breaking out of a loop and continuing
• The 'select' loop
• The 'getopts' Command
• Processing arguments
• The getopts and OPTARG variable
• The OPTIND variable
• Array variables
• Substituting and counting
• Using integer variables as element numbers
• Functions and function libraries
• Displaying current shell functions
• Declaring and using functions
• Variable scope
• Function libraries and recursion
• Managing input and output
• File descriptors
• Reading / writing using file descriptors
• Redirecting, parameter lists and 'here' documents
• Creating parameter lists from input lines
• Traps and signals
• Common signals
• The trap and stty commands
• Regular expressions
• Regular expressions
• Metacharacters
• The grep command
• Introduction to 'awk'
• Record processing
• Pattern matching and relational expressions
• 'awk' variables
• Variables, strings and arithmetic operations
• 'awk' user defined variables
• Environment variables
• Arithmetic operations
• String manipulation
• Formatted output
• Command line arguments
• 'awk' flow control
• Conditional 'if', while and for loops
• Arrays
• 'getline', 'next' and 'exit'
• Processing arrays
• Associative arrays
• Stream editing with 'sed'
• Substituting text
• Deleting and printing lines
• Reading and writing files
• Multiple 'sed' editor functions