Hi,

[I recognise this is a bash question, but I'd like to limit it to Slack users, forgive if it trangresses etiquette]

My .bashrc file is full of aliases and I carry it around on my USB, it's become pretty much indispensible to me.

In effort to make even more use of them, I was wondering if I could use the arguments that come after the alias-command within the alias as defined in the .bashrc.

I mean, take tar. You want to tar up a current directory tree quickly, but you want to be able to specify the name of the tar file each time (i.e. by putting it as an argument to the alias). Is it possible to have the alias recognise the argument that comes after it and so use it as the tar file name?

What I do now, is write an alias which uses a generic name for the tarfile and then I rename it after using the alias. Of course, this is straightforward in a small script, but an alias? Actually,

alias tart='tar file.tar * && mv file.tar'

does appear to work. Though it complains "tar: file.tar: file is the archive; not dumped"

I suppose that I expect that aliases are really just expansions, and that this is not possible. I expect you need to include a function (maybe) in the .bashrc.

Another way could be write out the name of the tarfile you want to use on the prompt line and press return. THis would sotr eit in the !$ expansion. Then the alias might recognise the !$ expansion. However, that's unelegant. [ehem, just tried it, alias won't expand the !$. Now, that's a sign of their being pretty elementary tools.]

Cheers!

I'm no expert so maybe this isn't what your after, but here goes anyway:

The arguments after any command are refered to as $1 $2 $n for nth argument, so:

alias play="mp3blaster $1"

would take one argument.

then,

play /home/chris/Music

would be equivilent to

mp3blaster /home/chris/Music

nb: the same thing works for functions too, of course, but is not exclusive to them.

does that help? I'm still quite new to linux so forgive me if I've missed the point!!!

thats quite correct.
If you want even more functionality try making it a function

then something like this would work

tart()
{
tar $1 *
mv $1
echo "DONE"
return 0
}

You get the gist? the main thing you wanted was I guess the fact that $1 represents the arg
I couldn't quite understand what you wanted to do there so I guess my function will be wrong.

@ChrisScott

I was trying to get a similar thing to work with a mkdir/cd compound command, and $1 just doesn't work. Take for example:

$ alias mcd="echo +$1+;echo +$1+"

$ mcd test
++
++ test

I had to make a function out of it to get it to work properly:

$ mcd() { echo +$1+; echo +$1+; }

$ mcd test
+test+
+test+

$ mcd() { mkdir -p $1; cd $1; }

bigler@homemachine ~
$ mcd test

bigler@homemachine ~/test
$