NeedRestart::UI assumes STDOUT is a terminal, fails to run when piped

[guillaume-uH57J9]

I encounter issues running needrestart in an unattended manner because NeedRestart::UI assumes STDOUT is a terminal.

This bug was previously logged downstream as Debian bug #859387. I am logging this here as I believe the issue is upstream.

The following command:
DEBIAN_FRONTEND=noninteractive needrestart -q -r l | logger -s

Gives the following error:
Unable to get Terminal Size. The TIOCGWINSZ ioctl didn't work. The COLUMNS and LINES environment variables didn't work. The resize program didn't work. The stty program didn't work. at /usr/share/perl5/NeedRestart/UI.pm line 50.

Explanation of the command:

• Variable DEBIAN_FRONTEND=noninteractive tells debconf not to wait for user interaction regarding kernel updates. This is a workaround for List-only mode should not require interaction for kernel updates #67
• Command logger -s sends the output to syslog and STDERR. The actual command is not important, the catch here is NeedRestart::UI doesn't expect the output to be piped to another process, it expect instead STDOUT to be a terminal.

[guillaume-uH57J9]

As an alternative I've tried using the batch mode as follows, which works without a terminal:
needrestart -q -b

But it appears to ignore the quiet option and always prints needrestart's version, which is not desired.

So still no solution in sight.

[guillaume-uH57J9]

I submitted a pull request along with an example command to run needrestart in a unattended manner, and produce a human-readable output:

needrestart -u NeedRestart::UI::stdio -q -r l | logger -s

[liske]

Hi,

the batch options does indeed ignore the quiet option intentional. The batch option prints all findings in a parsable format (used by DE-IBH/apt-dater) for further processing so the quiet option does not make any sense. I'm considering to add another option to needrestart to enforce a unattended/non-interactive mode.

HTH,
Thomas