I'm using ARMBIAN 5.25 stable Debian GNU/Linux 8 (jessie) 3.4.113-sun8i and on my raspberry pi the bash script below works without any errors/

 

#!/bin/sh
i=$(cat /etc/hour.conf)
new_i=$((i+1))
if [ "$new_i" -gt 15 ]; then
  new_i=0
fi
echo "$new_i">/etc/hour.conf
echo "$new_i"
 

However on the OrangePiZero , I get the following error message?

 

./loops: 3 ./loops: Illegal number: new_i

 

Any help would be greatly appreciated!

 

Adding the $ to in front of the i and removing one set of brackets and the double quote marks in the if statement fixed the issue. Not sure why the raspberry pi didn't have a problem with it, but its working now!

 

#!/bin/sh
i=$(cat /etc/hour.conf)
new_i=$(($i+1))
if [ $new_i -gt 15 ]; then
 new_i=0
fi
echo "$new_i">/etc/hour.conf
echo "$new_i"