How to read a file content in ash into an argument?

Question

I'm trying to read a file which holds a single number in ash shell. The bash way of doing so

ARG=`cat /tmp/tempfile`

doesn't work and I get that ARG doesn't hold anything after this line of code.

Answer 1

try to surround it with quotes to have it not stopped at the first newline:

ARG="`cat /tmp/tempfile`"

or

ARG="$(cat /tmp/tempfile)"

or

read ARG  </tmp/tempfile #only 1st line will be read