Increment variable value by 1 (shell programming)
command-line, debugging, shell, ubuntu, variables
Solution
You can use an arithmetic expansion like so:
i=$((i+1))
or declare `i` as an integer variable and use the `+=` operator for incrementing its value.
declare -i i=0
i+=1
or use the `((` construct.
((i++))
Problem
I can't seem to be able to increase the variable value by 1. I have looked at tutorialspoint's Unix / Linux Shell Programming tutorial but it only shows how to add together two variables. I have tried the following methods but they don't work: ``` i=0 $i=$i+1 # doesn't work: command not found echo "$i" $i='expr $i+1' # doesn't work: command not found echo "$i" $i++ # doesn't work*, command not found echo "$i" ``` How do I increment the value of a variable by 1?