How to pass command line arguments to a shell alias?
Question
How do I pass the command line arguments to an alias? Here is a sample:
alias mkcd='mkdir $1; cd $1;'
But in this case the $xx is getting translated at the alias creating time and not at runtime. I have, however, created a workaround using a shell function (after googling a little) like below:
function mkcd(){ mkdir $1 cd $1 }
Just wanted to know if there is a way to make aliases that accept CL parameters.
BTW - I use 'bash' as my default shell.
Solution
You found the way: create a function instead of an alias. The C shell has a mechanism for doing arguments to aliases, but bash and the Korn shell don't, because the function mechanism is more flexible and offers the same capability.
OTHER TIPS
Just to reiterate what has been posted for other shells, in Bash the following works:
alias blah='function _blah(){ echo "First: $1"; echo "Second: $2"; };_blah'
Running the following:
blah one two
Gives the output below:
First: one
Second: two
You cannot in ksh, but you can in csh.
alias mkcd 'mkdir \!^; cd \!^1'
In ksh, function is the way to go. But if you really really wanted to use alias:
alias mkcd='_(){ mkdir $1; cd $1; }; _'
To quote the bash man page:
There is no mechanism for using arguments in the replacement text. If arguments are needed, a shell function should be used (see FUNCTIONS below).
So it looks like you've answered your own question -- use a function instead of an alias
You may also find this command useful:
mkdir dirname && cd $_
where dirname is the name of the directory you want to create
The easiest way, is to use function not alias. you can still call a function at any time from the cli. In bash, you can just add function name() { command } it loads the same as an alias.
function mkcd() { mkdir $1; cd $1 ;}
Not sure about other shells
You actually can't do what you want with Bash aliases, since aliases are static. Instead, use the function you have created.
Look here for more information: http://www.mactips.org/archives/2008/01/01/increase-productivity-with-bash-aliases-and-functions/. (Yes I know it's mactips.org, but it's about Bash, so don't worry.)
I found that functions cannot be written in ~/.cshrc file .. Here in alias which takes arguments
for example, arguments passed to 'find' command
alias fl "find . -name '\!:1'"
Ex: >fl abc
where abc is the argument passed as !:1
This works in ksh:
$ alias -x mkcd="mkdir \$dirname; cd \$dirname;"
$ alias mkcd
mkcd='mkdir $dirname; cd $dirname;'
$ dirname=aaa
$ pwd
/tmp
$ mkcd
$ pwd
/tmp/aaa
The "-x" option make the alias "exported" - alias is visible in subshells.
And be aware of fact that aliases defined in a script are not visible in that script (because aliases are expanded when a script is loaded, not when a line is interpreted). This can be solved with executing another script file in same shell (using dot).
I think you are able to do it with shell functions if you are using bash: http://www.cyberciti.biz/faq/linux-unix-pass-argument-to-alias-command/
Here's a simple example function using python. You can stick in ~/.bashrc
You gotta have a space after the first left curly bracket
The python command needs to be in double quotes to get the variable substitution
Don't forget that semicolon at the end
function count(){ python -c "for num in xrange($1):print num";}
$ count 6
0
1
2
3
4
5
$
An empty alias will execute its args:
alias DEBUG=