If statement doesn't execute argument - bash

Question

GNU nano 2.7.4 File: /home/pi/initDisplay/initDisplay.sh
#!/usr/bin/env bash
#HDMI connection?
rm -f hdmi.name
tvservice -n 2>hdmi.name
HDMI_NAME=`cat hdmi.name`
echo $HDMI_NAME
if [ "$HDMI_NAME" == "[E] No device present" ]; then
LCD_ON=`cat /boot/config.txt | grep "#CONFIGURAZIONEHDMI"`
echo $LCD_ON
if [ "$LCD_ON" == "#CONFIGURAZIONEHDMI" ]; then
echo "reboot con la configurazione LCD"
sudo rm -f /boot/config.txt
sudo cp /boot/config_lcd.txt /boot/config.txt
sleep 2
sudo reboot -n
fi
else
HDMI_ON=`cat /boot/config.txt | grep "#CONFIGURAZIONELCD"`
echo $HDMI_ON
if [ $HDMI_ON == "#CONFIGURAZIONELCD" ]; then
echo "reboot con la configurazione HDMI"
sudo rm -f /boot/config.txt
sudo cp /boot/config_hdmi.txt /boot/config.txt
sleep 2
sudo reboot -n
fi
fi
Doesn't start the arg of if statement with $LCD_ON. When I try to execute it, it doesn't return what I expect. Now it returns:
[E] no device detected
#CONFIGURAZIONEHDMI
but it doesn't start to replace file and reboot.
P.S.: The user and the file have privileges to do it
And I already set chmod 777 the file

Answer 1

There might be more on the line that matches, such as extra whitespace, so the equality test doesn't match exactly.
If you want to test whether a matching line exists in a file, you can just test the exit status of grep, rather than storing the output in a variable.
if grep -q "#CONFIGURAZIONEHDMI" /boot/config.txt; then
echo "reboot con la configurazione LCD"
sudo rm -f /boot/config.txt
sudo cp /boot/config_lcd.txt /boot/config.txt
sleep 2
sudo reboot -n
fi
The -q option tells grep not to print the matching line, it just sets its exit status.