in Bash, how to not include extra arguments in an alias?

Question

I am trying to do something like

alias ftp='echo do not use ftp. Use sftp instead.'

just so that ftp will not be accidentally used. But I noticed that

ftp abcd.com

will cause the command to echo

do not use ftp. Use sftp instead. abcd.com

because the abcd.com is taken to be an argument for echo.

Is there a way to make Bash not add abcd.com to the substitution, or make echo not take it as extra arguments? (Is there a solution for each approach?)

I supposed I could make it

alias ftp='sftp'

but I just want to make the command stop all together to remind myself not to use ftp.

Answer 1

When you define an alias, the command you set is run instead of the one you wrote. This means that when you run ftp abc.com, what is actually executed is

echo do not use ftp. Use sftp instead abc.com

A simple solution is to use a function instead of an alias:

ftp(){ echo 'do not use ftp. Use sftp instead'; }

Alternatively, you could use printf as suggested by Costas:

alias ftp="printf 'do not use ftp. Use sftp instead\n'"

Answer 2

alias ftp='echo do not use ftp. Use sftp instead. # '

Answer 3

Just put a space and the comment character # at the end of the alias string:

alias ftp='echo do not use ftp. Use sftp instead. #'
ftp abcd.com
do not use ftp. Use sftp instead.

This will cause the parameters to be treated as a comment. Just do not forget to add a space before # otherwise it will not be interpreted as a separate token after the alias expansion.