To change the prompt…
PS1='C:\\\w> '
That will set your prompt to:
C:\~>
as opposed to
lab46:~$
which is set up by having the following…
PS1='\h:\w\$ '
CTRL+r will allow us to search through previously used commands.
“history” lists out our previous entries in the terminal.
MultiTasking!!!??!?!?
Linux is a Multi User Multi Tasking System… That's how we can all log into Lab46 and work at the same time.
Background vs. Foreground
Stopped vs. Running
| Key Press: | Result: |
|---|---|
| CTRL+c | SIGINT |
| CTRL+d | EOF |
| CTRL+z | SIGUSP/SIGSTOP |
Running a program with an ampersand “&” will try to run it in the background. In Unix, a server/service is called a “Daemon”.
“sleep” is pretty nifty… This allows us to run a command later (if we choose to do so.)
(sleep 30; ls)&
This will wait 30 seconds, run ls, and stay in the background. The ls will appear in our terminal.
A running program is called a process.
ps will show us process statuses on our current terminal.
kill -l shows us the 64 different ways to kill a process
ps shows us our running processes. ps aux shows all of the running processes on the system.
If we say “kill -1 29606”
That will kill the process with the ID of 29606 (found when you use ps) by using the SIGHUP method to kill it. That's a hangup. It's more “friendly.” kill -9 is the most abrasive way to kill things. kill -9 -1 is bad. Don't do that. It kills everything that is “kill-able.”
Arrays!
Instead of having a variable that must be typed and increased EVERY SINGLE TIME, we can use an array.
Example…
read battle1exp read battle2exp read battle3exp
We can do this…
for 1);do
echo -n "Enter score: "
read score
battleexp[$i]=$score
done total=0 for2);do
let total=$total+${battleexp[$i]}
done echo “Your total score is $total”
Scripts vs. Programs
Interpreted Code - HTML, bash, vbscript, PHP, Python, javascript, etc…
Compiled Code - C, C++, Pascal, Fortran, etc…