bash, set variable from script to memory

I need "set" variable from script to memory (global) and read it again in second run of this script with defined last state of this variable.

Script.

echo $count
let "count=count+1"
export $count
echo $count

This shows me 1 when I run this script again. I need 1, and in the case I run the script again, I need 2, in case of third run 3, etc.

I thought export do this, but it is not working.

Thanks.

1 Answer

The export shell builtin only exports variables (and their values) to child processes of the current shell.

AFAIK you'd need to use some kind of state file to store a value between invocations. You can locate the file on a RAM-based filesystem such as /var/run if you want the value to be stored "to memory".

See for example:

• Is it possible to have bash variables persist between runs

• Variable in Bash Script that keeps it value from the last time running