Efficient Linux at the Command Line

Appendix B. If You Use a Different Shell

This book assumes your login shell is bash, but if it’s not, Table B-1 may help you adapt the book’s examples for other shells. The checkmark symbol ✓ indicates compatibility—the given feature is similar enough to bash’s that examples in the book should run correctly. However, the feature’s behavior may differ from bash’s in other ways. Read any footnotes carefully.

Note

Regardless of which shell is your login shell, scripts that begin with #!/bin/bash are processed by bash.

To experiment with another shell installed on your system, simply run it by name (e.g., ksh) and press Ctrl-D when finished. To change your login shell, read man chsh.

Table B-1. bash features supported by other shells, in alphabetical order

bash feature	dash	fish	ksh	tcsh	zsh
alias builtin	✓	✓, but alias name does not print the alias	✓	No equals sign: alias g grep	✓
Backgrounding with &	✓	✓	✓	✓	✓
bash -c	dash -c	fish -c	ksh -c	tcsh -c	zsh -c
bash command	dash	fish	ksh	tcsh	zsh
bash location in /bin/bash	/bin/dash	/bin/fish	/bin/ksh	/bin/tcsh	/bin/zsh
BASH_SUBSHELL variable
Brace expansion with {}	Use seq	Only {a,b,c}, not {a..c}	✓	Use seq	✓
cd - (toggling directories)	✓	✓	✓	✓	✓
cd builtin	✓	✓	✓	✓	✓
CDPATH variable	✓	set CDPATH value	✓	set cdpath = (dir1 dir2 …​)	✓
Command substitution with $()	✓	Use ()	✓	Use backquotes	✓
Command substitution with backquotes	✓	Use ()	✓	✓	✓
Command-line editing with arrow keys	✓	✓a	✓	✓
Command-line ...