adds test

certificates/essentials/test.md

@@ -221,13 +221,13 @@
 	* E) `touch newfile.txt afile.txt`
 2. You want to copy a directory, `MyFiles`, to a USB flash drive that uses the FAT filesystem. The contents of `MyFiles` are as follows:
 
-	```bash
-	$ ls -l MyFiles/
-	total 276
-	-rw-r--r-- 1 jen  users 129840 Nov 8 15:13 contract.odt
-	-rw-r--r-- 1 rod  users  42667 Nov 8 15:12 outline.pdf
-	-rw-r--r-- 1 sam  users 105979 Nov 8 15:12 Outline.PDF
-	```
+		```bash
+		$ ls -l MyFiles/
+		total 276
+		-rw-r--r-- 1 jen  users 129840 Nov 8 15:13 contract.odt
+		-rw-r--r-- 1 rod  users  42667 Nov 8 15:12 outline.pdf
+		-rw-r--r-- 1 sam  users 105979 Nov 8 15:12 Outline.PDF
+		```
 
 The USB flash drive is mounted at `/media/usb`, and so you type `cp -a MyFiles /media/`. What problem will occur when you attempt to copy these files?
 	* A) The command will fail because it tries to create links.
@@ -410,10 +410,10 @@ The USB flash drive is mounted at `/media/usb`, and so you type `cp -a MyFiles /
 	* E) Run a spell checker on the script to ensure it contains no bugs.
 2. Describe the effect of the following short script, `cp1`, if it's called as `cp1 big.c big.cc`:
 
-	```bash
-	#!/bin/bash
-	cp $2 $1
-	```
+		```bash
+		#!/bin/bash
+		cp $2 $1
+		```
 
 	* A) It has the same effect as the `cp` command, copying the contents of `big.c` to `big.cc`.
 	* B) It compiles the C program `big.c` and calls the result `big.cc`.
@@ -430,12 +430,12 @@ The USB flash drive is mounted at `/media/usb`, and so you type `cp -a MyFiles /
 5. True or false: Valid looping statements in Bash include `for`, `while`, and `until`.
 6. True or false: The following script launches three simultaneous instances of the `terminal` program.
 
-	```bash
-	#!/bin/bash
-	terminal
-	terminal
-	terminal
-	```
+		```bash
+		#!/bin/bash
+		terminal
+		terminal
+		terminal
+		```
 
 7. You've written a simple shell script that does nothing but launch programs. In order to ensure that the script works with most user shells, what should its first line read?
 8. What command can you use to display prompts for a user in a shell script?