Add learning objectives for Bash Shell

[steve-crouch]

There are no learning objectives for the Bash Shell lessons, although they do already exist for the original materials upon which they are based. A suggested ported set of learning objectives (curated to what's in the UNIVERSE-HPC version) are:

• Introducing the shell
  • Describe the benefits of using the shell over other styles of interface
• Files and Directories
  • Translate an absolute path into a relative path and vice versa.
  • Construct absolute and relative paths that identify specific files and directories.
  • Use options and arguments to change the behaviour of a shell command.
  • Demonstrate the use of tab completion and explain its advantages.
• Creating things
  • Create a directory hierarchy that matches a given diagram.
  • Create files in that hierarchy using an editor or by copying and renaming existing files.
  • Delete, copy and move specified files and/or directories.
• Pipes and filters
  • Explain the advantage of linking commands with pipes and filters.
  • Combine sequences of commands to get new output
  • Redirect a command’s output to a file.
  • Briefly describe how pipes channel input and output between piped commands.
  • Explain what usually happens if a program or pipeline isn’t given any input to process.
• Shell scripts
  • Write a shell script that runs a command or series of commands for a fixed set of files.
  • Run a shell script from the command line.
  • Write a shell script that operates on a set of files defined by the user on the command line.
• Loops
  • Write a loop that applies one or more commands separately to each file in a set of files.
  • Trace the values taken on by a loop variable during execution of the loop.
  • Explain the difference between a variable’s name and its value.
  • Re-run recently executed commands without retyping them.