nl_langinfo ¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9799919799/functions/nl_langinfo.html
Portability problems fixed by Gnulib:
CODESET is not supported on some platforms:
OpenBSD 3.8.
ALTMON_1 to ALTMON_12 are not supported on some
platforms:
glibc 2.26, musl libc, macOS 14, NetBSD 8.0, OpenBSD 7.5, AIX 7.2, HP-UX 11.31, Solaris 11.4, Haiku, Cygwin 2.9.
ABALTMON_1 to ABALTMON_12 are not supported on many
platforms:
glibc 2.41, musl libc, macOS 14, NetBSD 10.0, OpenBSD 7.6, AIX 7.3, HP-UX 11.31, Solaris 11.4, Haiku, Cygwin 3.5.
ERA, ERA_D_FMT, ERA_D_T_FMT,
ERA_T_FMT, ALT_DIGITS are not supported on some platforms:
OpenBSD 7.5.
Portability problems not fixed by Gnulib:
nl_langinfo(CODESET) always
returns "US-ASCII".
nl_langinfo(CRNCYSTR) returns the
empty string, although the local currency symbol, as returned by
localeconv()->currency_symbol, is non-empty.
nl_langinfo(ABMON_1) ... nl_langinfo(ABMON_12) are full month
names, not abbreviated month names.