nixcraft

Linux Shell Scripting Tutorial (LSST) v2.0

Una interessante guida per apprendere al meglio il bash scripting è possibile trovarla anche nel sito della nixcraft (registrandosi gratuitamente potete staricare anche la versione PDF ).

Il sommario è questo.

Chapter 1: Quick Introduction to Linux

• What Is Linux?
• Who created Linux?
• Where can I download Linux?
• How do I Install Linux?
• Linux usage in everyday life
• What is Linux Kernel?
• What is Linux Shell?
• Unix philosophy
• But how do you use the shell?
• What is a Shell Script or shell scripting?
• Why shell scripting?
• Chapter 1 Challenges

Chapter 2: Getting Started With Shell Programming

• The bash shell
• Shell commands
• The role of shells in the Linux environment
• Other standard shells
• Write a simple shell script – “Hello World!”
  • Starting a script with Shebang line (#!)
  • Comments in a script
  • Setting up permissions on a script
  • Execute a script
  • Debug a script
• Chapter 2 Challenges

Chapter 3:The Shell Variables and Environment

• Variables in shell
  • Assign values to shell variables
  • Default shell variables value
  • Rules for Naming variable name
  • Display the value of shell variables
  • Quoting
  • The export statement
  • Unset shell and environment variables
  • Getting User Input Via Keyboard
• Perform arithmetic operations
  • Create an integer variable
  • Create the constants variable
• Bash variable existence check
• Customize the bash shell environments
  • Recalling command history
  • Path name expansion
  • Create and use aliases
  • The tilde expansion
  • Startup scripts
    • Using aliases
    • Changing bash prompt
    • Setting shell options
    • Setting system wide shell options
• Chapter 3 Challenges

Chapter 4: Conditionals Execution (Decision Making)

• Bash structured language constructs
• Test command
• if structures to execute code based on a condition
• If..else..fi
• Nested ifs
• Multilevel if-then-else
• The exit status of a command
• Conditional execution
• Logical AND &&
• Logical OR ||
• Logical Not !
• Conditional expression using [ (portable version)
• Conditional expression using [[
• Numeric comparison
• String comparison
• File attributes comparisons
• Shell command line parameters
  • How to use positional parameters
  • Parameters Set by the Shell
  • Create usage messages
  • Exit command
• The case statement
  • Dealing with case sensitive pattern
• Chapter 4 Challenges

Chapter 5: Bash Loops

• The for loop statement
• Nested for loop statement
• The while loop statement
  • Use of : to set infinite while loop
• The until loop statement
• The select loop statement
  • Exit the select loop statement
• Using the break statement
• Using the continue statement
• Command substitution
• Chapter 5 Challenges

Chapter 6: Shell Redirection

• Input and Output
• Standard input
• Standard output
• Standard error
• Empty file creation
• /dev/null discards unwanted output
• here documents
• here strings
• Redirection of standard error
• Redirection of standard output
• Appending redirected output
• Redirection of both standard error and output
• Writing output to files
• Assigns the file descriptor (fd) to file for output
• Assigns the file descriptor (fd) to file for input
• Closes the file descriptor (fd)
• Opening the file descriptors for reading and writing
• Reads from the file descriptor (fd)
• Executes commands and send output to the file descriptor (fd)
• Chapter 6 Challenges

Chapter 7: Pipes and Filters

• Linking Commands
• Multiple commands
• Putting jobs in background
• Pipes
  • How to use pipes to connect programs
  • Input redirection in pipes
  • Output redirection in pipes
  • Why use pipes
• Filters
• Chapter 7 Challenges

Chapter 8: Traps

• Signals
  • What is a Process?
  • How to view Processes
  • Sending signal to Processes
  • Terminating Processes
  • Shell signal values
• The trap statement
• How to clear trap
• Include trap statements in a script
• Use the trap statement to catch signals and handle errors
• What is a Subshell?
  • Compound command
  • exec command
• Chapter 8 Challenges

Chapter 9: Functions

• Writing your first shell function
  • Displaying functions
  • Removing functions
• Defining functions
• Writing functions
• Calling functions
• Pass arguments into a function
  • local variable
• Returning from a function
• Shell functions library
  • Source command
• Recursive function
• Putting functions in background
• Chapter 9 Challenges

Chapter 10: Interactive Scripts

• Menu driven scripts
  • Getting information about your system
• Bash display dialog boxes
  • dialog customization with configuration file
  • A yes/no dialog box
  • An input dialog box
  • A password box
  • A menu box
  • A progress bar (gauge box)
  • The file selection box
  • The form dialog for input
• Console management

• Display KDE / GTK+ GUI dialog
  • zenity: Shell Scripting with Gnome
  • kdialog: Shell scripting with KDE
• notify-send: Send desktop notifications
• Chapter 10 Challenges