Update Linux Introduction

Linux-Introduction.md

@@ -1,6 +1,22 @@
 ## Documentation pages: 
 Merlin usage: https://lsm-hpce.gitpages.psi.ch/merlin6/introduction.html
 
+Linux cheat sheet (one of many): https://www.guru99.com/linux-commands-cheat-sheet.html
+
+
+## Useful keys in the Terminal
+
+`|` , "pipe" connects output of one command to another (see example 'grep' below)
+
+`~` , "tilde" stands for "home" directory
+
+`tab` , "tab" autocompletion of paths and commands in the terminal. Extremely useful to check if the command is actually valid. 
+
+`ctrl + c` , **not** "copy", it actually kills a process in the terminal.If you want to copy use middle mouse or mousepad-specific features. 
+
+`ctrl + Z` , then `bg ` puts a running process in the terminal into the background , same as starting a process with `&`. Example: `relion & `
+
+
 
 ## Some useful commands in the Terminal: 
 
@@ -12,6 +28,7 @@ Merlin usage: https://lsm-hpce.gitpages.psi.ch/merlin6/introduction.html
 - editing files:  `emacs <name-of-file>` or `nedit <name-of-file> `or `vim (advanced) ` 
 - showing file contents in the terminal: `more <name-of-file>` 
 - showing the size of folders/files in one specific folder: `du –max-depth 1 -h `
+- searching for a specific pattern in a file: `more <name-of-file> | grep 'pattern' `
 
 
 ## ~/.bashrc  file 
@@ -31,3 +48,4 @@ Most important info:
 - `/data/user/$username:` 1TB , no backup 
 - `/psi/home/$username:` 10GB , Backup 
 
+Data, Data Processing , Conda etc. should be in `/data/user/$username`, as it needs quite some storage, very important things that need to be backup-ed and are small go to `/psi/home/$username`