Re: [coreutils] [PATCH] tests: fix a printf portability issue

[Jim Meyering]

Pádraig Brady wrote:
> not all printf commands support \xhh
>
> diff --git a/tests/misc/sort-debug-keys b/tests/misc/sort-debug-keys
> index 57a52a6..4e8beff 100755
> --- a/tests/misc/sort-debug-keys
> +++ b/tests/misc/sort-debug-keys
> @@ -275,7 +275,7 @@ printf "2.,,3\n2.4\n" | sort -s -k1n --debug
>  printf "2,,3\n2.4\n" | sort -s -k1n --debug
>
>  # -z means we convert \0 to \n
> -printf "1a\x002b\x00" | sort -s -n -z --debug
> +printf "1a\0002b\000" | sort -s -n -z --debug

That would accommodate an inferior printf builtin function,
with the implication that all printf uses should do the same.
It may be hard or at least tedious to audit existing uses --
then it'd be good (but more work) to enforce the no-\xHH policy.

Since this is the coreutils, we have the option of a more sustainable
policy: use "env" to ensure the test runs the printf binary that we've
just built in this package:

    # printf '\xHH' is not portable with some built-ins. FIXME: list an offender
    # Use env to force use of the one from coreutils.
    env printf '1a\x002b\x00' | sort -s -n -z --debug

That also gives printf more test coverage.

Also, please use single quotes in cases like this,
where nothing is intended to be shell-expanded.