functions.sh: Add more useful explainations

functions.sh

@@ -1,16 +1,81 @@
 #!/bin/bash
 
-fuck(){
+######################################################
-    echo "fuck you"
+## filename: functions.sh
-    echo ""
+## Description: Learn how to use functions in bash
+## Notes: Fucntions have to be called or 'run' to use them
+##        Run a function by typing it's name
+##        variable names such as 'user_input' can be named anything
+##        you cannot run a function before you create/defne it
+#####################################################
+
+slap(){
+
+    echo -n "who wants to get slapped: " # use echo command without automatic newline
+    read user_input # "read": reads what user typed and store in variable called 'user_input'
+
+     # use double brackets to make code run more reliably in bash (does not work in other shells)
+    if [[ $user_input = "me" ]];then
+        echo "you gets a slap"
+    elif [[ $user_input = "you" ]];then
+        echo "you still get slapped"
+    fi
 }
 
-ipp(){
+block_tutorial(){
-    echo Public IP
+    # Show how to test if something is a device or not
-    curl -s icanhazip.com
+
-    echo
+    echo -n "enter a block device name: " # ask and print the question
-    echo Local IP
+    read user_input # read the users response and puts it into the variable "user_input"
-    /sbin/ifconfig enp3s0 | grep 'inet addr:' | cut -d: -f2 | awk '{ print $1}'
+
+    if [[ -b $user_input ]];then # the user enters a device name and -b tests if it is a block device
+        echo "This is a block device"
+    elif [[ ! -b $user_input ]];then # "!" specifically checks if user_input is NOT a block device
+        echo "This is not a block device"
+    fi
 }
-fuck
+
-ipp
+file_tutorial(){
+    # Show how to test if something is a file or not
+    
+    echo -n "enter file name: " #asks for a filename to test
+    read user_input # reads the users response and puts it into the variable "user_input"
+
+    if [[ -f $user_input ]];then 
+        echo "This is a file"
+    elif [[ ! -f $user_input ]];then
+        echo "This is not a file"
+    fi
+}
+
+folder_tutorial(){
+    #Show if something is a folder or not
+
+    echo -n "enter folder path: " #asks for folder path
+    read user_input # reads the users response and puts it into the variable "user_input"
+
+    if [[ -d $user_input ]];then
+        echo "this is a folder"
+    elif [[ ! -f $user_input ]];then
+        echo "this is not a folder"
+    fi
+}
+
+empty_variable(){
+    # Show if a variable it empty or not
+
+    echo -n "Enter some text: " #asks user to enter random text
+    read some_text # read what user typed and store it into variable called "some_text"
+
+    if [[ -z $some_text ]];then
+        echo "There is nothing stored in the varialbe 'some_text'"
+    elif [[ ! -z $some_text ]];then
+        echo "The user has entered in some text!"
+    fi
+}
+# run functions created above or comment them to stop them from running
+slap
+block_tutorial
+file_tutorial
+folder_tutorial
+empty_variable