Thanks for sharing. While tweaking the formatting, I accidentally introduced a typo which led to me spending a few minutes hunting for a fix for "sudo: unable t

Thanks for sharing. While tweaking the formatting, I accidentally introduced a typo which led to me spending a few minutes hunting for a fix for "sudo: unable to initialize PAM: No such process" without having to reboot :( Anyway, here's the version of your one-liner I used to preserve the spacing used in the rest of the file: sudo perl -pi -e 's/(pam_smartcard.so)/$1\nauth sufficient pam_tid.so/' /etc/pam.d/sudo