Read string from file and convert into an int [closed]

Question

I have a txt file with ONLY a number inside; it can be any number, how can i read it from bash and convert it into an int?

As i said, the only thing in the file is the number, no other thing, but when reading it, bash gets it as a string.

Thanks in advance!

Answer 1

Use declare or typeset:

typeset -i variable=$(cat filename)