… I found 15:
+-----+------------------------------------------------------------+
| # | name |
+-----+------------------------------------------------------------+
| 1 | The Bourne Shell | sh | +-----+------------------------------------------------------------+
| 2 | The Bash Shell | bash |
+-----+------------------------------------------------------------+
| 3 | The C shell | csh |
+-----+------------------------------------------------------------+
| 4 | The Korn Shell | ksh | +-----+------------------------------------------------------------+
| 5 | The ZSH Shell | zsh |
+-----+------------------------------------------------------------+
| 6 | The TENEX C Shell | tcsh |
+-----+------------------------------------------------------------+
| 7 | The Fish Shell | fish | +-----+------------------------------------------------------------+
| 8 | The Ion shell | ion |
+-----+------------------------------------------------------------+
| 9 | The Dash Shell | dash |
+-----+------------------------------------------------------------+
| 10 | Eshell | eshell | +-----+------------------------------------------------------------+
| 11 | The rc Shell | rc |
+-----+------------------------------------------------------------+
| 12 | The Scheme Shell | scsh |
+-----+------------------------------------------------------------+
| 13 | The Xonsh Shell | xonsh | +-----+------------------------------------------------------------+
| 14 | The Oh Shell | oh |
+-----+------------------------------------------------------------+
| 15 | The Elvish Shell | elvish |
+-----+----------------------------------------------------------[1]Which shell am I currently using?
To find out which shell you’re using, go ahead and execute either of the following commands on your terminal:
echo $0alternatively,
echo $SHELL(https://askubuntu.com/questions/590899/how-do-i-check-which-shell-i-am-using)
Which shells are available in my device?
There are at least two ways to check which shells are available in your device. Using a cat command:
cat /etc/shells(https://unix.stackexchange.com/questions/140286/how-to-find-list-of-available-shells-by-command-line)
Or the following regular expression:
grep '^[^#]' /etc/shells(https://www.geeksforgeeks.org/list-out-all-the-shells-using-linux-commands/)
DO NOT MISS
In reading stuff to learn about this/prepare this short post, this translator/comparator came up:
https://hyperpolyglot.org/unix-shells
It documents syntax differences between bash, fish, ksh, tcsh and zsh.
Background
What is a shell
A shell is a program that provides an interface between a user and an operating system (OS) kernel.[2]
>>> did I unintentionally leave any out? Please let me know!
__________________________________________________________________
[1] https://www.ubuntupit.com/linux-shell-roundup-15-most-popular-open-source-linux-shells/
[2] https://www.thegeekdiary.com/unix-linux-what-is-a-shell-what-are-different-shells/
[3] https://www.unix.com/man-page/osx/1/chpass/
Consulted: