Re: exec/read -s bug?

[Lars Schneider]

> On Aug 19, 2018, at 8:45 PM, Lars Schneider <larsxschneider@gmail.com> wrote:
> 
> 
>> On Aug 19, 2018, at 6:33 PM, Lars Schneider <larsxschneider@gmail.com> wrote:
>> 
>> Hi,
>> 
>> consider this script:
>> 
>>      #!/bin/bash
>>      [ "`whoami`" = "root" ] || {
>>        exec sudo -u root "$0" "$@"
>>      }
>>      read -s -p "enter stuff: " stuff
>> 
>> If I run the script as normal user (not root!) and I abort the "read -s -p"
>> call with "ctrl-c", then my shell is still in silent mode.
>> 
>> I can consitently replicate that behavior on Ubuntu 14.04.5 LTS (Trusty) 
>> and BASH 4.3.11(1)-release (x86_64-pc-linux-gnu) as well as BASH 4.3.30.
>> 
>> I also installed BASH 4.4.18 from source and I can replicate the issue.
> 
> I did a mistake: The problem _was_ fixed with BASH 4.4.18.
> Further testing revealed that it is fixed with 4.4. too but not in Bash-4.3 
> patch 46.
> 
> I think the following item in the release notes corresponds to the problem:
> 
> oo. Fixed a bug that caused bash to not clean up readline's state, including
>     the terminal settings, if it received a fatal signal while in a readline()
>     call (including `read -e' and `read -s').
> 
> Does anyone see a workaround to set the readline state properly
> for older BASH versions?

OK, I found a work around:

        [ "`whoami`" = "root" ] || {
          exec sudo -u root "$0" "$@"
        }

        function finish {
          stty echo echok
        }
        trap finish EXIT
        read -s -p "enter stuff: " stuff
        echo "answer: $stuff"

Cheers,
Lars