From 69bfec3a8f73c74f2a9044af69e87a209c81b9ef Mon Sep 17 00:00:00 2001
From: Vadym Furmanchuk <furmanchuk.v.y@gmail.com>
Date: Sun, 12 Dec 2021 01:07:27 +0200
Subject: [PATCH] TASK02: Add hot plugged/unplugged hardware detector script

Add bash task
---
 02_bash/hwdetect/hwdetect.sh | 45 ++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)
 create mode 100755 02_bash/hwdetect/hwdetect.sh

diff --git a/02_bash/hwdetect/hwdetect.sh b/02_bash/hwdetect/hwdetect.sh
new file mode 100755
index 0000000..460bb24
--- /dev/null
+++ b/02_bash/hwdetect/hwdetect.sh
@@ -0,0 +1,45 @@
+#!/bin/bash
+
+OLDLIST="/tmp/oldlist"
+NEWLIST="/tmp/newlist"
+
+update_list()
+{
+	ls /dev/ > $1
+}
+
+get_diff()
+{
+	local oldlist_num=`wc -l < $OLDLIST`
+	local newlist_num=`wc -l < $NEWLIST`
+	local diff=$(($oldlist_num - $newlist_num))
+	
+	if [ $(($diff + 0)) -eq 0 ]; then
+		return 0
+	fi
+	
+	return 1
+}
+
+print_diff()
+{
+	comm -23 <(sort $OLDLIST) <(sort $NEWLIST) | awk '{print $1 " unplugged" }'
+
+	comm -13 <(sort $OLDLIST) <(sort $NEWLIST) | awk '{print $1 " plugged" }'
+}
+
+
+
+update_list $OLDLIST
+
+while :
+do
+	sleep 1
+	update_list $NEWLIST
+	get_diff
+	diff=$?
+	if [ $(($diff + 0)) -ne 0 ]; then
+		print_diff
+		cp $NEWLIST $OLDLIST
+	fi	
+done