Re: [PATCH 1/4] test: add a library to detect an en_US.UTF-8 locale

Yann Droneaud [off-list ref] writes:

Yann Droneaud [off-list ref] writes:

Since one can't rely on "locale" command availability nor its -a output,
perl script t/lib-locale.pl first use setlocale() and langinfo(CODESET)
to search for a working en_US.UTF-8 locale among many name variants.

If this fail, the script fallback to "locale" usage with two steps:
- try the "charmap" keyword, for example LC_ALL=en_US locale charmap
- then try "-a" option and match a pattern looking to the
  locale names

Signed-off-by: Yann Droneaud <redacted>
---
 t/lib-locale.pl |  167 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 167 insertions(+), 0 deletions(-)
 create mode 100755 t/lib-locale.pl

The remainder of the series looks more or less sane, but a new 170-line
script somehow feels a bit overengineered solution to a minor problem that
has already been solved in a much simpler way.

+# try to execute "locale -a" command
+# this command is not always available and
+# output format is not normalized
+#
+use IPC::Open3;
+use File::Spec;
+
+open(NULLR, "<", File::Spec->devnull) || die "Can't open devnull: $!";
+open(NULLW, ">", File::Spec->devnull) || die "Can't open devnull: $!";
+
+my $pid = open3("<&NULLR", \*LOCALES, ">&NULLW" , "locale", "-a") || die "Can't launch locale -a: $!";
+
+while(<LOCALES>) {
+     chomp;
+     if (/(en_US\.([\w-]+))/i) {
+	 if (codeset_check($2)) {
+	     $locale = $1;
+	     last;
+	 }
+     }
+}
+
+waitpid($pid, 0);

You are trying to buy something with the complexity of Open3 for doing
this logic, over a bog-naive "for (`locale -a`) { ... }", but is that
something really worth the money?

"lib-locale.pl" is a gross misnomer for this script.

It may be a good helper to be used in 2/4 (test_utf8), but later people
may want to have more helper feature in something called "lib-locale", not
just "pick a single UTF-8 locale randomly from available ones on the
system" (especially when ab/i18n starts moving again).  I'd suggest either
to (1) rename it "pick-utf8-locale.pl" (i.e. honest naming) or (2) prepare
the helper command to be extensible from the beginning, i.e. require a
command word e.g. "lib-locale.pl pick-utf8-locale" to trigger the
currently implemented feature (i.e. forward looking naming).