These scripts are written with Bash-specific syntax and thus require the Bash shell specifically.

[tteck]

Taking this into account, the scripts have been updated to include a check to verify if the default shell is set to Bash. If the default shell is not Bash, the script will exit.

This update aims to prevent difficult-to-troubleshoot issues that can arise from using non-Bash shells (apologies to Zsh users).

[szymswiat]

To clarify: do we have to set bash as the default shell from now on? Executing e.g. bash -c "$(wget -qLO - https://github.com/tteck/Proxmox/raw/main/ct/docker.sh)" is not enough? Use of basename "$SHELL" in 0b604d2 was intended?

[tteck]

If you haven't changed the default shell, you're good. However, using Zsh may cause issues due to its slightly different syntax and behavior compared to Bash, particularly with constructs such as arrays, variable expansion, and command substitution.

The basename command is used to extract the filename from a given path. For example, if $SHELL contains /bin/bash, then basename "$SHELL" will output bash, similarly, if $SHELL contains /usr/bin/zsh, basename "$SHELL" will output zsh.

In the newly created shell_check function, if the default shell is not set to bash, the script will exit.

Proxmox/misc/build.func

Lines 75 to 83 in 9d96202

	shell_check() {
	if [[ "$(basename "$SHELL")" != "bash" ]]; then
	clear
	msg_error "Your default shell is currently not set to Bash. To use these scripts, please switch to the Bash shell."
	echo -e "\nExiting..."
	sleep 2
	exit
	fi
	}

Here is a recent example, #2440 (comment), there are many more scattered throughout.

[tteck]

@szymswiat were you using Zsh as your shell while experiencing the issue in #2410?

[szymswiat]

@tteck my base shell is zsh however I have run it with bash -c "$(wget -qLO - https://github.com/tteck/Proxmox/raw/main/ct/omv.sh)" which utilizes bash. I don't think checking $SHELL variable is a good approach since it contains path to login shell and it won't change even after entering bash. Please refer to https://unix.stackexchange.com/questions/522907/shell-environment-variable-still-points-to-zsh-after-using-bash. I think checking BASH_VERSION is more reliable. For now as a workaround I need to set SHELL=/bin/bash bash -c "$(wget -qLO - https://github.com/tteck/Proxmox/raw/main/ct/omv.sh)" to let it work.

[tteck]

When you use bash -c to execute the script, you're indeed ensuring that the script is interpreted and executed with the Bash shell. However, if the script relies on Bash-specific features or behaviors, it may not work properly when executed with Zsh, even if it's invoked through bash -c. I've observed this in several reported issues.

So, the $SHELL variable will still point to /bin/zsh, even though the script is being executed with bash -c. This addresses the issue by disallowing the use of Zsh.

[lightmaster]

@szymswiat Thanks for this. I had forgotten you could set a variable prior to running a command. Makes it a lot easier to keep using the scripts while this bizarre issues still persists.

[lightmaster]

@szymswiat A better workaround I found is to setup an alias in zsh, so that every time you run a command that starts with bash as it's first word, instead of actually running bash foo bar, you'll run SHELL=/bin/bash bash foo bar. This includes copy/pasting these scripts that start with bash -c, so it'll automatically prepend SHELL=/bin/bash in front of bash -c.

1. Add this to the end of your ~/.zshrc (or create if it doesn't exist and add this to it)

if [ -f ~/.aliases ] && [ -r ~/.aliases ]; then
        . ~/.aliases
fi

2. Create ~/.aliases and add this to it

alias bash="SHELL=/bin/bash bash"

3. Reload ZSH with the new .zshrc

. ~/.zshrc

[tteck]

I've identified several issues that I believe stem from having zsh set as the default shell, and I suspect there may be many more.
#2440 (comment)
#2410 (comment)
#2200 (comment)
#2411 (reply in thread)
#524 (comment)
#1698 (comment)