Text editing and processing

vi (which stands for visual) is the standard Linux text editor. Unlike most text editors, it is modal. Learning vi is essential if one wants to become a good Linux system administrator.

The following aspects of vi need to be known:

• Starting vi
• Moving around
• Moving to lines
• Editing text
• Search & replace
• Quitting vi

Text Processing

One area where Linux excels is the processing of enormous volumes of text using pipes and filters.

We will start by looking at text streams and filters in order to master:

• Piping
• wc, head, and tail
• expand, unexpand, and tr
• sort and uniq
• cut, paste, and join
• sed etc.

Then we will cover all aspects of redirection:

• Output redirection
• Input redirection

Finally, we will learn about regular expressions as used in most text processing utilities in Linux.