This chapter has aimed to give you a working knowledge of the Bash command line shell. The history of the shell was explained, providing insight into the various shells and their origin. Some simple yet useful commands for managing processes and the filesystem were dealt with. Commands to perform common administrative tasks were also examined. To assist the power user , some keyboard shortcuts and control key mappings that abbreviate common tasks were examined. Command-line syntax, including the use of quotes and the concept of environment variables , was also examined, as was the ability to redirect input and output. Some job control features, such as the ability of the shell to perform multiple tasks at the same time, were explained. Additionally, this chapter dealt with the ability to run unattended tasks. Finally, the chapter examined the most powerful and flexible aspect of the shell, the ability to construct complex programs from simple shell commands (that is, shell scripting).