How to pass command line arguments to a shell alia

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.

Answer 1

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.)

Answer 2

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

Answer 3

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).

Answer 4

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

Answer 5

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/

Answer 6

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
$