On Thu, 8 Oct 2020 at 08:55, Karel Zak <kzak@xxxxxxxxxx> wrote: > On Thu, Oct 08, 2020 at 08:50:39AM +0200, Stanislav Brabec wrote: > > Fix su -s <tab> that reports invalid chsh -l. > > "cat /etc/shells" and "chsh -l" get the same output on my system, why > "chsh -l" is invalid? > > chsh -l uses getusershell() glibc function. I guess "$(</etc/shells)" was done to avoid exec, but it is not the same as "$(chsh -l)" because the chsh will not list comment lines. What I get is: $ x=$(</etc/shells); echo $x # Pathnames of valid login shells. # See shells(5) for details. /bin/sh /bin/bash /usr/bin/git-shell /bin/dash /bin/zsh /usr/bin/zsh Compared to: $ chsh --list-shells /bin/sh /bin/bash /usr/bin/git-shell /bin/dash /bin/zsh /usr/bin/zsh I hope it is obvious why cat(1) or bash memory mapping that $(<file) is isn't the best way to read /etc/shells when using output as completion options. -- Sami Kerola http://www.iki.fi/kerolasa/
