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Accepted
Yura Shinkarev
Asked: 2017-11-09 03:52:57 +0800 CST

Read string with $USER variable as text and resolve it

  • 772

I have some config-file. Config-file contains string: LocalPath /media/$USER

I read config-file in bash-script:

while read var value
do
    export "$var"="$value"
done < my-conf-file.conf

So, I can use $LocalPath in bash-script. It equals: /media/$USER, but I want to have: /media/user1 (user1 is my user).

How I can implement it?

bash

2 Answers

  1. Best Answer

    read does not expand variables from your config file.

    You can verify that:

    $ read username
$USER
$ echo $username
$USER

    This answer on Stackoverflow gives a solution.
    Change your script to this to make it expand variables:

    while read var value
do
    export "$var"="$value"
done < <(envsubst < my-conf-file.conf)
    • 9

  2. As Kyle Strand suggested in a comment, the easiest solution is to make the config file a Bash script:

    export LocalPath=/media/$USER

    Then source it from your main script:

    source my-conf-file.sh

    Or if you have a bunch of variables, and don't want to type export for every one, make the config file like this:

    set -a
LocalPath=/media/$USER
set +a
    • 1