Install bash-doc by entering the following commands in the terminal:
sudo apt update sudo apt install bash-doc
Documentation and examples for the GNU Bourne Again SHell
Bash is an sh-compatible command language interpreter that executes commands read from the standard input or from a file. Bash also incorporates useful features from the Korn and C shells (ksh and csh). . This package contains the distributable documentation, all the examples and the main changelog.