MacOS – What happens if you used “rm -rf *” in /Users or /Users/someUser

Put this into your ~/.bashrc ~/.bash_profile or where-ever you like it:

alias copyLastCmd='fc -ln -1 | awk '{$1=$1}1' | pbcopy '

After opening a new window (or running source ~/.bash_profile) you should be able to run copyLastCmd and have the command in the clipboard.

To explain what's going on: you're basically using "fix command" (fc) to get you the last command, remove both leading and trailing whitespace for nicer formatting with awk and then copy it into your Mac's pasteboard with pbcopy.

EDIT:

Now that we know that you want to copy to paste into another terminal tab, there's another option: Add these lines to your ~/.bashrc ~/.bash_profile or where-ever you like it:

shopt -s histappend
PROMPT_COMMAND='$PROMPT_COMMAND; history -a; history -n'

Then, once you have some new tabs open (let's call them "tab A" and "tab B"):

1. Execute any command in tab A
2. Switch to tab B, press enter on an empty line, giving you a "fresh" new line (and thus re-evaluating the history)
3. use the up arrow once and you should have the command you've just entered in tab A.

EDIT 2: I've replaced the usage of sed with awk in the original answer above, to take care of both leading and trailing whitespace .

First, a few things to note:

On the Mac the files /etc/passwd and /etc/master.passwd are only consulted when the Mac is booted into single user mode.

I'm not sure what you mean by "set the master password" for the Mac. Do you mean set the password for the account 'root'?

Usually you use the passwd command to change passwords from the command line (there is no master.passwd command) but you can't use it from a script as it requires input.

To change a password in a script you need to use the dscl command.

Here is an example :

dscl . -passwd /Users/tonyw newpass

Note that the above would have to be run as root, which means your script would have to be run by root. Otherwise you have to add authentication to the dscl command thus:

dscl . -u Admin -P adminpassword -passwd /Users/tonyw newpass

The user Admin must have administrator privileges for the Mac.

(All of this is incredibly insecure as you have passwords in plain text in a script.)

Of course to set the password for 'root' just change the tonyw to root in the above.

Have a good look at dscl(1) to understand the options in the above.