Shortcuts, Aliases, and Macros¶
Shortcuts¶
Command shortcuts for long command names and common commands can make life more
convenient for your users. Shortcuts are used without a space separating them
from their arguments, like !ls
. By default, the following shortcuts are
defined:
?
- help
!
- shell: run as OS-level command
@
- run script file
@@
- run script file; filename is relative to current script location
To define more shortcuts, update the dict App.shortcuts
with the
{‘shortcut’: ‘command_name’} (omit do_
):
class App(Cmd):
def __init__(self):
shortcuts = dict(cmd2.DEFAULT_SHORTCUTS)
shortcuts.update({'*': 'sneeze', '~': 'squirm'})
cmd2.Cmd.__init__(self, shortcuts=shortcuts)
Warning
Shortcuts need to be created by updating the shortcuts
dictionary
attribute prior to calling the cmd2.Cmd
super class __init__()
method. Moreover, that super class init method needs to be called after
updating the shortcuts
attribute This warning applies in general to many
other attributes which are not settable at runtime.
Note: Command, alias, and macro names cannot start with a shortcut
Aliases¶
In addition to shortcuts, cmd2
provides a full alias feature via the
alias
command. Aliases work in a similar fashion to aliases in the Bash
shell.
The syntax to create an alias is: alias create name command [args]
.
Ex:alias create ls !ls -lF
Redirectors and pipes should be quoted in alias definition to prevent the
alias create
command from being redirected:
alias create save_results print_results ">" out.txt
Tab completion recognizes an alias, and completes as if its actual value was on the command line.
For more details run: help alias create
Use alias list
to see all or some of your aliases. The output of this
command displays your aliases using the same command that was used to create
them. Therefore you can place this output in a cmd2
startup script to
recreate your aliases each time you start the application
Ex:alias list
For more details run: help alias list
Use alias delete
to remove aliases
For more details run: help alias delete
Note: Aliases cannot have the same name as a command or macro
Macros¶
cmd2
provides a feature that is similar to aliases called macros. The major
difference between macros and aliases is that macros can contain argument
placeholders. Arguments are expressed when creating a macro using {#} notation
where {1} means the first argument.
The following creates a macro called my_macro that expects two arguments:
macro create my_macro make_dinner -meat {1} -veggie {2}
When the macro is called, the provided arguments are resolved and the assembled command is run. For example:
my_macro beef broccoli —> make_dinner -meat beef -veggie broccoli
Similar to aliases, pipes and redirectors need to be quoted in the definition of a macro:
macro create lc !cat "{1}" "|" less
To use the literal string {1}
in your command, escape it this way:
{{1}}
. Because macros do not resolve until after hitting <Enter>
,
tab completion will only complete paths while typing a macro.
For more details run: help macro create
The macro command has list
and delete
subcommands that function
identically to the alias subcommands of the same name. Like aliases, macros can
be created via a cmd2
startup script to preserve them across application
sessions.
For more details on listing macros run: help macro list
For more details on deleting macros run: help macro delete
Note: Macros cannot have the same name as a command or alias