Test for ${EDITOR} or fall-back to nano for text file editing

README.md

@@ -546,7 +546,7 @@ dtoverlay=disable-wifi
 #### Step 1: Edit wpa_supplicant.conf
 
 ```
-sudo nano /etc/wpa_supplicant/wpa_supplicant.conf
+sudo ${EDITOR} /etc/wpa_supplicant/wpa_supplicant.conf
 ```
 
 #### Step 2: Delete the relevant WiFi network block (including the 'network=' and opening/closing braces.

docs/Concurrent_Mode.md

@@ -29,7 +29,7 @@ How do I Enable Concurrent Mode?
 Edit the `Makefile` with a text editor:
 
 ```
-nano Makefile
+${EDITOR} Makefile
 ```
 
 Change the following line:

edit-options.sh

@@ -20,7 +20,20 @@ then
 	exit 1
 fi
 
-nano /etc/modprobe.d/${OPTIONS_FILE}
+# Check if ${EDITOR} is an executable or try to default to nano or finally complain if it's not installed.
+if ! [ -x "${EDITOR}" ]
+then
+        EDITOR="$(which nano 2>/dev/null)"
+        if ! [ -x "${EDITOR}" ]
+        then
+                echo "No text editor found (default: nano)."
+                echo "Please install one and set the EDITOR variable to point to it."
+                echo "When you have an editor, please run \"sudo ./${SCRIPT_NAME}\""
+                exit 1
+        fi
+fi
+
+${EDITOR} /etc/modprobe.d/${OPTIONS_FILE}
 
 read -p "Do you want to apply the new options by rebooting now? [y/N] " -n 1 -r
 echo    # move to a new line

install-driver.sh

@@ -87,13 +87,17 @@ then
 	exit 1
 fi
 
-# check to ensure nano is installed
-if ! command -v nano >/dev/null 2>&1
+# Check if ${EDITOR} is an executable or try to default to nano or finally complain if it's not installed.
+if ! [ -x "${EDITOR}" ]
 then
-	echo "A required package is not installed."
-	echo "Please install the following package: nano"
-	echo "Once the package is installed, please run \"sudo ./${SCRIPT_NAME}\""
-	exit 1
+	EDITOR="$(which nano 2>/dev/null)"
+	if ! [ -x "${EDITOR}" ]
+	then
+		echo "No text editor found (default: nano)."
+		echo "Please install one and set the EDITOR variable to point to it."
+		echo "When you have an editor, please run \"sudo ./${SCRIPT_NAME}\""
+		exit 1
+	fi
 fi
 
 # support for the NoPrompt option allows non-interactive use of this script
@@ -353,7 +357,7 @@ then
 	echo
 	if [[ $REPLY =~ ^[Yy]$ ]]
 	then
-		nano /etc/modprobe.d/${OPTIONS_FILE}
+		${EDITOR} /etc/modprobe.d/${OPTIONS_FILE}
 	fi
 
 	read -p "Do you want to reboot now? (recommended) [y/N] " -n 1 -r