Question

I am creating a .bash_profile script, and I have run into a small problem.

Here is a snippet of my code:

echo -n "Welcome "
whoami
echo -n "!"

I would like the output to give something like this:

Welcome jsmith!

… instead of this:

Welcome jsmith
!

How can I get all of this onto one line?

Any help is greatly appreciated. If it helps, I’m using the Bash Shell, on Ubuntu Server 10.04 LTS.

Answer 1

You can insert $(command) (new style) or `command` (old style) to insert the output of a command into a double-quoted string.

echo "Welcome $(whoami)!"

Note: In a script this will work fine. If you try it at an interactive command line the final ! may cause you trouble as ! triggers history expansion.

Command Substitution

Command substitution allows the output of a command to replace the command name. There are two forms:

$(command)

or

`command`

Bash performs the expansion by executing command and replacing the command substitution with the standard output of the command, with any trailing newlines deleted [emphasis added].