In bash, how to make a comparison and assign the boolean result to a variable

Question

I am doing a string comparison between a variable and a constant. The result of the comparison, either true or false, is assigned to another variable.

LABEL=$("${INPUT}" == "flag");

However, I am failing. Any suggestion?

Answer 1

You can use expr:

INPUT='flag'
LABEL=$(expr "${INPUT}" == "flag")
echo "$LABEL"
1

INPUT='flab'
LABEL=$(expr "${INPUT}" == "flag")
echo "$LABEL"
0