cannot be used to specify default arguments for a command. Instead, this must be done by adding items to the collection $PSDefaultParameterValues, one of the PowerShell preference variables. Viewing currently defined aliases To view defined aliases the following commands can be used: alias # Used without arguments; displays a list of all current aliases alias -p # List aliases in a way that allows re-creation by sourcing the output; not available in 4DOS/4NT and PowerShell alias myAlias # Displays the command for a defined alias Overriding aliases In Unix shells, it is possible to override an alias by quoting any character in the alias name when using the alias. For example, consider the following alias definition: alias ls='ls -la' To override this alias and execute the ls command as it was originally defined, the following syntax can be used: 'ls' or \ls In the 4DOS/4NT shell it is possible to override an alias by prefixing it with an asterisk. For example, consider the following alias definition: alias dir = *dir /2/p The asterisk in the 2nd instance of dir causes the unaliased dir to be invoked, preventing recursive alias expansion. Also the user can get the unaliased behaviour of dir at the command line by using the same syntax: *dir Changing aliases In Windows PowerShell, the set verb can be used with the alias cmdlet to change an existing alias: set-alias ci cls The alias ci will now point to the cls command. In the 4DOS/4NT shell, the eset command provides an interactive command line to edit an existing alias: eset /a cp The /a causes the alias cp to be edited, as opposed to an environment variable of the same name. Removing aliases In Unix shells and 4DOS/4NT, aliases can be removed by executing the unalias command: unalias copy # Removes the copy alias unalias -a # The -a switch will remove all aliases; not available in 4DOS/4NT unalias * # 4DOS/4NT equivalent of `unalias -a` - wildcards are supported In Windows PowerShell, the alias can be removed from the alias:\ drive using remove-item: remove-item alias:ci # Removes the ci alias Features Chaining An alias usually replaces just the first word. But some shells, such as and , allow a sequence or words to be replaced. This particular feature is unavailable through the function mechanism. The usual syntax is to define the first alias with a trailing space character.