Opening of the Way

https://en.wikipedia.org/wiki/C_shell

Ubuntu Linux
https://ubuntu.com/

https://ubuntu.com/


Unix Shells
https://ubuntu.com/

https://en.wikipedia.org/wiki/Unix_shell

https://en.wikipedia.org/wiki/Unix_shell

https://en.wikipedia.org/wiki/Bash_(Unix_shell)

Johnson, Chris F. A
Title   Pro Bash programming : scripting the GNU/Linux shell / Chris F.A. Johnson, Jayant Varma  (2015)   but a caution!


A practical guide to Linux commands, editors, and shell programming / Mark G. Sobell ; coauthored by Matthew Helmke. (2018), seem to need to know about csh and bash, and especially about expandability.