How to save a file with multi lines to a variable

[Bill Wang]

I need save a file to variable for one bamboo server build plan

In build, I need echo the variable and save to a file which I want to get exact format. 

How to do that?

    echo "${bamboo_key}" > /key

[Bill Wang · Accepted solution]

I fixed it by myself.

cat file |base64   # in some OS, the output are multiple lines as well, just remove "\n"

then copy the string into the variable in bamboo plan

When run the build, add below line

echo ${bamboo_key}|base64 -d > /key