Replace a string in a file with contents copied from another file

Question

I have figured out and tried replacing strings with the help of gsed -i command like this:

gsed -i \'s/sdkUniqueKey=\"\"/sdkUniqueKey=\"123\"/g\         


        

Answer 1

If I have properly understood your question, the following should do the trick:

#!/bin/bash

fileToBeRead="key.txt" #Whatever

var=$(tr -d '[:blank:]\n' < $fileToBeRead)
sed -i "s#sdkPrivateKey=\"\"#sdkUniqueKey=\"$var\"#g" AppConstants.txt

Since the key contains backslashes/slashes you should use a different separator for sed (e.g. #) or the sentence will be misparsed.

EDIT:

KEY="$var" perl -pi -e 's/sdkPrivateKey=""/sdkUniqueKey="$ENV{KEY}"/g' AppConstants.txt

perl can be used instead of sed in order to avoid sed's separator issues. Check out @DennisWilliamson's comment below.