modify basic filestructure

It's unclear what's 'basic', so `basic/` notes have been mostly moved.
The remainder became `shell/`.

system/kill.md

@@ -0,0 +1,74 @@
+---
+title: "kill"
+tags: [ "basics" ]
+---
+
+If you want to kill a program in a graphical environment, open a terminal and type:
+
+# Graphical Programs
+
+```sh
+xkill
+```
+
+Then click on the application which you want to kill.
+
+# All Programs
+
+To kill a program, find it with:
+
+```sh
+pgrep discord
+```
+
+This will give you the UUID, e.g. `19643`.
+
+Kill the program with:
+
+```sh
+kill 19643
+```
+
+# Types of Kill
+
+To see an ordered list of termination signals:
+
+```sh
+kill -l
+```
+
+> 1) SIGHUP   2) SIGINT   3) SIGQUIT  4) SIGILL   5) SIGTRAP
+
+> 6) SIGABRT  7) SIGBUS   8) SIGFPE   9) SIGKILL 10) SIGUSR1
+
+> 11) SIGSEGV 12) SIGUSR2 13) SIGPIPE 14) SIGALRM 15) SIGTERM
+
+
+You can select these levels with a '- number'.
+Higher numbers are roughly equivalent to insistence.
+
+For example:
+
+```sh
+kill -1 3498
+```
+
+This roughly means 'maybe stop the program, if you can, maybe reload'.
+
+Or the famous:
+
+```sh
+kill -9 3298
+```
+
+This means 'kill the program dead, now, no questions, dead'.
+
+**Beware** - if Firefox starts another program to connect to the internet, and you `kill -9 firefox`, this will leave all of Firefox's internet connection programs ("children") still there, but dead and useless.
+
+# Sobriquets
+
+- A dead program which sits there doing nothing is known as a 'zombie'.
+- A program which is run by another program is called a 'child program'.
+- A child whose parent program is dead is called an 'orphan'.
+- A child who remains running despite being useless because the parent is dead is called an 'orphan zombie'.
+