Re: [Libguestfs] [nbdkit PATCH] tests: Better quoting for cleanup_fn

On 07/26/22 12:17, Laszlo Ersek wrote: > On 07/26/22 10:11, Richard W.M. Jones wrote: >> On Tue, Jul 26, 2022 at 07:13:41AM +0200, Laszlo Ersek wrote: >>> On 07/25/22 16:02, Eric Blake wrote: >>>> + for (( _i = 0; _i < $_cleanup_hook_count; ++_i )); do >>>> + local -n _hook=_cleanup_hook$_i >>>> + "${_hook[@]}" >>> >>> BTW, "nameref" variables seem like a relatively new addition to bash; >>> for example RHEL7 does not have them. Interestingly, the RHEL7 manual >>> also does not document a nameref-like construct that *does* work in >>> RHEL7, namely: >>> >>> $ bar=foo >>> $ baz=bar >>> $ echo ${!baz} >>> foo >> >> Indeed it doesn't work on RHEL 7, eg: >> >> $ make && make -C tests check TESTS=test-eflags.sh >> >> leaves tests/eflags.{err,out} around. >> >> Do you have a patch for this? > > This should work: > > local hook=_cleanup_hook$_i > eval "\${${hook}[@]}" Sigh, nesting quoting is always fun; I forgot the outermost quotes. So please make that: eval "\"\${${hook}[@]}\""

> > Thanks > Laszlo > >> >> [...] >>> I wonder if the bash release notes mention "nameref" as a more flexible >>> version of "indirect expansion"... Hm, nameref was new in bash-4.3 >>> <https://lwn.net/Articles/589566/>;, and RHEL7 has bash-4.2.46-35.el7_9, >>> so the lack of "nameref" is understandable (not that it matters for >>> upstream nbdkit :)); indirect expansion is not mentioned however as a >>> similar feature. >> >> Actually I'd like to keep things working on RHEL 7 if possible. It's >> still a widely used RHEL release. >> >> Rich. >> >