maybe a bug in bash?

[Sebastian Luhnburg]

Hello,

I'm not sure, if I found a bug or if I miss some understanding, but I 
want to report it, if it is a bug. Please tell me more, if I'm right or 
if it is my mistake.

I have a script, in which I have an password (I get it from a password 
manager - no excitement ;D ). The password begin with a $ and have an & 
in middle. I want to use this password in an here document, which inject 
some commands into a SSH-Connection (for simplification, I use the bash 
instead of ssh in the test script below). To use the password in the 
here document, I need to escape the special character. For this, I use 
printf. The echo command in the here document give me the right output. 
But if I run a subshell in the here document, the first \ for the $ is 
being cut away. But why? At the moment I think this is a bug. But if it 
is no bug, can you tell me why bash do this?

You find a test script here:

#!/usr/bin/env bash

initial_password="\$abc&xyz"
echo "initial password: " $initial_password
printf -v password '%q' $initial_password
echo "initial password with escaped characters: " $password
bash << EOF
echo "password in here document: " ${password@Q}
/bin/bash -c "echo 'password in subshell in here document: ' ${password@Q}"
EOF


The output:


initial password:  $abc&xyz
initial password with escaped characters:  \$abc\&xyz
password in here document:  \$abc\&xyz
password in subshell in here document:  $abc\&xyz

Thank you very much!

Mit freundlichen Grüßen Sebastian Luhnburg IT 
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