It’s a bash command that writes an other command to your .bashrc files.
Bash is the default shell on most modern *nix distribution like MANY Linux distribution.
root@computer:/# is the prompt of a debian like system, it tells us that we are the root user (admin) of the computer named computer and that we are working on the main root directory (/). The command itself follows the prompt.
echo is a command that prints the double-quoted text that follows.
The >> symbols redirect the output of the previous command to a file. Because there is two symbols it’s appended to the file, if there were only one the file would be overridden.
.bashrc is a file runned by bash when you open a new shell (login physical terminal or ssh, oppening a terminal gui etc…)
So the “ls -laR /” command is runned each time you open a terminal once you have executed my signature. ls is a short for list and is used to list the content of a directory. The -a tag stands for all, so even hidden content (with a name starting with a dot) will be listed. The -l tag adds extra information, and make each element use a full line. The -R tag stands for recursive, and make the sub folders be listed as well.
So it spams the terminal with lots of data each time you login. It can be stopped by a keyboard interrupt (Ctrl + c).
