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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.


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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."


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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 ((i=0;i<12;i=i+1));do
        echo -n "Enter score: "
        read score
        battleexp[$i]=$score
done
total=0
for((i=0;i<12;i=i+1));do
        let total=$total+${battleexp[$i]}
done
echo "Your total score is $total"

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Scripts vs. Programs

Interpreted Code - HTML, bash, vbscript, PHP, Python, javascript, etc...

Compiled Code - C, C++, Pascal, Fortran, etc...
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