shopt

1. shopt is a command line tool used in Unix-like systems like Linux to manipulate shell options.
2. It allows users to view and modify various settings and behaviors of the shell.
3. To see the current shell options, you can simply use the shopt command without any arguments.
4. shopt -s followed by an option name enables the specified shell option.
5. shopt -u followed by an option name disables the specified shell option.
6. Some commonly used shell options include extglob, nullglob, globstar, nocaseglob, nocasematch, and histappend.
7. The extglob option enables extended globbing patterns that provide additional matching abilities.
8. The nullglob option allows pattern-based matches to expand to nothing if there are no matches.
9. The globstar option enables recursive matching using the ** pattern, useful for recursive file searches.
10. The histappend option appends commands to the history file instead of overwriting it, preserving command history across shell sessions.