IMHO, bourne shell backticks `...` have been anachronistic for some time, and we've arranged with gnulib's init.sh so that all of coreutils' tests can safely use $(...) instead. That has covered most new tests. This series removes/replaces all legacy `...` uses.
There are a few remaining in init.sh and check.mk, and one in the stdbuf test, but that's it. I'll add a syntax-check to keep it that way. [PATCH 1/4] tests: convert one `...` expression manually [PATCH 2/4] tests: convert nearly all `...` expressions to $(...) [PATCH 3/4] tests: use perl's qx!...! rather than `...` [PATCH 4/4] tests: remove nearly all remaining backticks
