Create an alias in bashrc file [duplicate]

Question

In Linux terminal, normally I can copy files from another unix server using:

scp -r [email protected]:/data/filename ./

which secure copies the remote file to my current directory. I've made sure this command line works well before I did anything below.

To save time of typing the long front part, I create an alias for scp -r [email protected]:, and receive arguments for /data/filename and ./ from command line.

Opening the ~/.bashrc file, first I tried

alias scpfile="scp -r [email protected]:'$1' '$2'"

In command line, I typed scpfile /data/filename ./, but I got an error message as follows:

error: unexpected filename: .

Then I tried another one

function scpfile() {
    scp -r [email protected]:$1 $(pwd)
}

or

function scpfile() {
    scp -r [email protected]:"$1" "$(pwd)"
}

In command line, I typed scpfile /data/filename, but it's also wrong with error message:

/data/filename: No such file or directory

Can someone help if you know the answer to it?

Moreover, I've tried the answers shown in Make a Bash alias that takes a parameter, but still not working!

Answer 1

The Bash documentation (Info manual) says:

There is no mechanism for using arguments in the replacement text, as in csh. If arguments are needed, use a shell function (see Shell Functions).

and

For almost every purpose, shell functions are preferred over aliases.

If you need to develop a custom command that takes argument to which it can refer by position, you write a function.

This looks right:

function scpfile() {
    scp -r [email protected]:"$1" "$(pwd)" 
}

Except, there is no advantage of using "$(pwd)" over just . (period), and it is less efficient, too. You would only need that in order to given a path argument to some tool that insists on requiring absolute paths.

The error message about the non-existence of $1 is coming from the remote host. scp is finding that /data/filename does not exist on the remote host.