"Eric Sunshine" <sunshine@xxxxxxxxxxxxxx> wrote: > On Mon, Apr 12, 2021 at 7:09 AM Ævar Arnfjörð Bjarmason > <avarab@xxxxxxxxx> wrote: > > Expand the t/check-non-portable-shell.pl checks to complain about the > > use of "-a" and "-o" to the "test" shell built-in to to mean "and" and > > "or", as opposed to using two "test" invocations with "&&" or "||". > > There aren't any portability issues with using that construct that I > > know of, but since Junio expressed a dislike of it in [1] and we've > > currently got no such constructs let's add it to the lint checking. I > > had various in-flight and WIP patches that used this construct. > It's not only Junio's dislike of `-a` and `-o` but also that they have > long been considered obsolescent by POSIX[1]. GNU has likewise warned > against it[2] for a few decades. > [1]: > https://pubs.opengroup.org/onlinepubs/9699919799/utilities/test.html#tag_20_128_16 > [2]: > https://www.gnu.org/savannah-checkouts/gnu/autoconf/manual/autoconf-2.70/html_node/Limitations-of-Builtins.html And also in Git's Documentation/CodingGuidelines, which motivates the advice with an example: test -n "$x" -a "$a" = "$b" is buggy and breaks when $x is "=", but test -n "$x" && test "$a" = "$b" does not have such a problem. -- Matthieu Moy https://matthieu-moy.fr/
