Get value of variable that contains a variable

Question

I have a variable $path with a value of "/home".

The variable $path is stored in a text file like this:

$path/programs

In my script, I am getting the line from the text file and setting it to a variable $ful_path

Problem: The variable $full_path is not getting the value of $path

echo $full_path

Result:

$path/programs

When I echo $path/programs from the command line, I do get /home/programs, it's only in the script as a variable it's being treated as a string.

How do you includes your script? What is the content of text file? — NoDataFound, Jan 20 '22 at 23:42
Text file $path/programs, NOTE that $path is an exported variable — Moses Davidowitz, Jan 20 '22 at 23:43
In the script, I grep “programs” from the file, into a variable. So the line $path/programs becomes the value of the variable. — Moses Davidowitz, Jan 20 '22 at 23:54
Could you edit your question to add the code on how you do that? (to be sure, even if I'm pretty sure you can use eval to do that, but there might less risky option there). — NoDataFound, Jan 21 '22 at 01:14

score 0 · Answer 1 · answered Jan 21 '22 at 10:18

You are probably doing something like :

export path=/home
echo '$path/programs' > test-file

full_path="$(cat test-file)"
echo "$full_path"

You can substitute variables with envsubst :

export path=/home
echo '$path/programs' > test-file

full_path="$(cat test-file | envsubst)"
echo "$full_path"

1 Answers1