How can I use debian_chroot in bashrc to identify the chroot env?

Question

I see the following in ~/.bashrc :

 if [ -z "${debian_chroot:-}" ] && [ -r /etc/debian_chroot ]; then
     debian_chroot=$(cat /etc/debian_chroot)
 fi

which means if the variable is not set, and the file exists and is readable, then set the file's content to the variable.

Am I supposed to write something to that file while preparing to chroot?
If yes, then I'll have to remove that file at the end of chroot job!

any explanation or suggestions will be appreciated.

Answer 1

This variable is just for building the default PS1 shell prompt down below:

PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w\$ '

So it is not essential to create the file, although it can be nice having the prompt identifying where you are.

As you can see -r tests for a file and if the user can read it, and if it exists, debian_chroot gets the content of it, so create /etc/debian_chroot inside the chroot with the wording you want. (inside, do not do it at the true root, as won't be inside the chroot )

So if your chroot is at /mnt, the file you would need to modify is /mnt/etc/debian_chroot (and not /etc/debian_chroot).