Why won't El Capitan run Homebrew after it has been successfully installed? I am very much new with all of this. I installed Homebrew from the Terminal and I am now stuck on figuring out why the terminal commands from brew that installs UPX is outputting errors, albeit, they derive from the first error. I am feeling that this might be a parameter or some sort of setting error. I matched the finished installation code from the site I used to get the brew download/install code with my successfully completed report from Terminal and everything lined up to a T.

This is the code I used:

mac$ brew install upx $ upx -d /Applications/Ableton Live 9 Suite.app/Contents/MacOS/Ableton Live 9 Suite ; exit;


Error ouput:

/usr/local/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaLoader): loading /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core/Formula/upx.rb


Error: No available formula with the name "$" 
//main error which obviously makes no sense to me, almost like an oxymoron. But again, it is probably the tidiest answer to solve and likely the easiest I will come across.

==&gt; Searching for a previously deleted formula...
Error: No previously deleted formula found.

==&gt; Searching for similarly named formuclae...
==&gt; Searching local taps...
Error: No similarly named formulae found.

==&gt; Searching taps...
==&gt; Searching taps on GitHub...
Error: No formulae found in taps.
logout
Saving session...
...copying shared history...
...saving history...truncating history files...
...completed.



  Was I supposed to restart Terminal? Mac? before trying to install UPX?
  Shell//Edit/New Window//Copy Special --> Choose Homebrew before UPX?


I have never done this live (other than suggested programs to write and compile code for school), let alone on a Mac; however, I am not sure any of that is relevant in the scope of learning.  

Albeit, I am not anymore familiar with the rest of the parameters than I am confident about trying to accomplish this which obviously, is not the end goal I have. I am not even sure it will work because of 3.92 beta. It is possible, if I find that it is no longer a beta but actually their 4th or most recent version, I will be able to decompress an exe file. As I understand, El Capitan and Sierra set up strange but mostly irrelevant security diagnostics.

I think I will give myself a reboot, breathe and start over. 

Any guidance is greatly appreciated! Thanks :)
It's not clear to me what commands you actually entered into the Terminal, but based on the output, it looks like they were not entered correctly.

brew install upx

This is one command.  It instructs brew to install the command-line program upx.  It needs to be entered on its own line, after which you press enter.

upx -d "/Applications/Ableton Live 9 Suite.app/Contents/MacOS/Ableton Live 9 Suite"

This is the second command.  It tells the program upx to do something to the file at the path specified, with the -d option switch.  It assumes your Ableton installation exists on that exact path /Applications/Ableton Live 9 Suite.app/Contents/MacOS/Ableton Live 9 Suite with that exact name.  I'm not familiar with upx, so I assume that you're using the correct syntax for that program's execution.

The $ in the command you copied are shell prompts, and not part of the actual commands.