This table below lists most features that I think would make you
choose one shell over another. It is not intended to be a definitive
list and does not include every single possible feature for every
single possible shell. A feature is only considered to be in a shell
if in the version that comes with the operating system, or if it is
available as compiled directly from the standard distribution. In
particular the C shell specified below is that available on SUNOS 4.*,
a considerable number of vendors now ship either tcsh or their own
enhanced C shell instead (they don't always make it obvious that they
are shipping tcsh.
Code:
| sh | csh | ksh | bash | tcsh | zsh | rc | es | ||||
| Job control | N | Y | Y | Y | Y | Y | N | N | |||
| Aliases | N | Y | Y | Y | Y | Y | N | N | |||
| Shell functions | Y(1) | N | Y | Y | N | Y | Y | Y | |||
| "Sensible" Input/Output redirection | Y | N | Y | Y | N | Y | Y | Y | |||
| Directory stack | N | Y | Y | Y | Y | Y | F | F | |||
| Command history | N | Y | Y | Y | Y | Y | L | L | |||
| Command line editing | N | N | Y | Y | Y | Y | L | L | |||
| Vi Command line editing | N | N | Y | Y | Y(3) | Y | L | L | |||
| Emacs Command line editing | N | N | Y | Y | Y | Y | L | L | |||
| Rebindable Command line editing | N | N | N | Y | Y | Y | L | L | |||
| User name look up | N | Y | Y | Y | Y | Y | L | L | |||
| Login/Logout watching | N | N | N | N | Y | Y | F | F | |||
| Filename completion | N | Y(1) | Y | Y | Y | Y | L | L | |||
| Username completion | N | Y(2) | Y | Y | Y | Y | L | L | |||
| Hostname completion | N | Y(2) | Y | Y | Y | Y | L | L | |||
| History completion | N | N | N | Y | Y | Y | L | L | |||
| Fully programmable Completion | N | N | N | N | Y | Y | N | N | |||
| Mh Mailbox completion | N | N | N | N(4) | N(6) | N(6) | N | N | |||
| Co Processes | N | N | Y | N | N | Y | N | N | |||
| Builtin artithmetic evaluation | N | Y | Y | Y | Y | Y | N | N | |||
| Can follow symbolic links invisibly | N | N | Y | Y | Y | Y | N | N | |||
| Periodic command execution | N | N | N | N | Y | Y | N | N | |||
| Custom Prompt (easily) | N | N | Y | Y | Y | Y | Y | Y | |||
| Sun Keyboard Hack | N | N | N | N | N | Y | N | N | |||
| Spelling Correction | N | N | N | N | Y | Y | N | N | |||
| Process Substitution | N | N | N | Y(2) | N | Y | Y | Y | |||
| Underlying Syntax | sh | csh | sh | sh | csh | sh | rc | rc | |||
| Freely Available | N | N | N(5) | Y | Y | Y | Y | Y | |||
| Checks Mailbox | N | Y | Y | Y | Y | Y | F | F | |||
| Tty Sanity Checking | N | N | N | N | Y | Y | N | N | |||
| Can cope with large argument lists | Y | N | Y | Y | Y | Y | Y | Y | |||
| Has non-interactive startup file | N | Y | Y(7) | Y(7) | Y | Y | N | N | |||
| Has non-login startup file | N | Y | Y(7) | Y | Y | Y | N | N | |||
| Can avoid user startup files | N | Y | N | Y | N | Y | Y | Y | |||
| Can specify startup file | N | N | Y | Y | N | N | N | N | |||
| Low level command redefinition | N | N | N | N | N | N | N | Y | |||
| Has anonymous functions | N | N | N | N | N | N | Y | Y | |||
| List Variables | N | Y | Y | N | Y | Y | Y | Y | |||
| Full signal trap handling | Y | N | Y | Y | N | Y | Y | Y | |||
| File no clobber ability | N | Y | Y | Y | Y | Y | N | F | |||
| Local variables | N | N | Y | Y | N | Y | Y | Y | |||
| Lexically scoped variables | N | N | N | N | N | N | N | Y | |||
| Exceptions | N | N | N | N | N | N | N | Y |
Key to the table above.
Y Feature can be done using this shell.
N Feature is not present in the shell.
F Feature can only be done by using the shells function
mechanism.
L The readline library must be linked into the shell to enable
this Feature.
Notes to the table above
1. This feature was not in the orginal version, but has since become
almost standard.
2. This feature is fairly new and so is often not found on many
versions of the shell, it is gradually making its way into
standard distribution.
3. The Vi emulation of this shell is thought by many to be
incomplete.
4. This feature is not standard but unoffical patches exist to
perform this.
5. A version called 'pdksh' is freely available, but does not have
the full functionality of the AT&T version.
6. This can be done via the shells programmable completion mechanism.
7. Only by specifing a file via the ENV environment variable.
