Bash
Text Processing centers on Bash grep Command - Search Text Using Patterns, plus the ideas that build on it.
The grep command is used to search for text patterns within files.
The awk command is used for pattern scanning and processing language.
The sed command is a stream editor used to perform basic text transformations on an input stream (a file or input from a pipeline).
The cut command is used to remove sections from each line of files.
The sort command is used to sort lines of text files.
The tail command is used to display the last part of files.
The head command is used to display the first part of files.