Start of check_user functions

documents/references.md

@@ -27,4 +27,14 @@ Various references used in project.
 
 
 ## References
-None so far.
+### Including other Script Files
+<https://stackoverflow.com/a/10823650>
+
+### Check Number of Passed Args
+<https://stackoverflow.com/a/6482403>
+
+### Get User's name
+<https://stackoverflow.com/a/19306837>
+
+### String Manipulation
+<https://stackoverflow.com/a/14703709>

utils.sh

 #!/usr/bin/env bash
+###
+ # A helper/utility script to be imported by other scripts.
+ #
+ # Intended to hold very common functionality (that's surprisingly not built into bash) such as string upper/lower,
+ # and checking current user value, and prompts of yes/no user input.
+ ##
+
+
+###
+ # Function to check if current username matches passed value.
+ # In particular, is used to check if user is sudo/root user.
+ ##
+function check_is_user () {
+
+    # Check number of passed function args. Continue.
+    if [[ $# == 1 ]]
+    then
+
+        local username=$USER
+        local check_user=$1
+
+        echo "user is ${username}."
+        echo "check_user is ${check_user}"
+
+    # Handle for too many args.
+    elif [[ $# > 1 ]]
+    then
+        echo "Too many args passed. Expected one arg of username to check against."
+        exit 1
+
+    # Handle for too few args.
+    else
+        echo "Too few args passed. Expected one arg of username to check against."
+        exit 1
+    fi
+}
+
+
+###
+ # Function to check if current username does not match passed value.
+ # In particular, is used to check if user is sudo/root user.
+ ##
+function check_is_not_user () {
+
+    # Check number of passed function args.
+    if [[ $# == 1 ]]
+    then
+
+        # Got the expected number of function args. Continue.
+        local username=$USER
+        local check_user=$1
+
+        echo "user is ${username}."
+        echo "check_user is ${check_user}"
+
+    # Handle for too many args.
+    elif [[ $# > 1 ]]
+    then
+        echo "Too many args passed. Expected one arg of username to check against."
+        exit 1
+
+    # Handle for too few args.
+    else
+        echo "Too few args passed. Expected one arg of username to check against."
+        exit 1
+    fi
+}