Bashdb Debug Shell Script

Recently started to learn bash shell, I do not know where to start, do not know what a good tool package to learn it. First Look for:

yao@wuyao:~$ Apt-cache Search Bash
Apparix-console-based Bookmark Tool for fast file system navigation
Backup-manager-command-line Backup Tool
Bash-the GNU Bourne Again SHell
Bash-builtins-bash loadable Builtins-headers & Examples
Bash-completion-programmable completion for the bash shell
Bash-completion-lib-programmable completion for the bash shell
Bash-doc-documentation and examples for the GNU Bourne Again SHell
Bash-minimal-the GNU Bourne Again SHell (minimal version)
Bash-static-the GNU Bourne Again SHell (static version)
Bashdb-bash Debugger
Biabam-bash Attachment Mailer

found that Bash-doc and bashdb, scholars are documents, there are a lot of example can be seen, the latter can be used to debug the shell, to install them:

yao@wuyao:~$ sudo apt-get install Bash-doc bashdb

Examples are put in/usr/share/doc/bash/examples.

Debug Bash in Emacs:

Debug Effect: