vasprintf
---------

LSB specification:
 https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-vasprintf.html

Documentation:

  * Variable Arguments Output Functions (libc),

  * man vasprintf.

Gnulib module: vasprintf or vasprintf-posix

Portability problems fixed by either Gnulib module vasprintf or vasprintf-posix:

  * This function is missing on some platforms: AIX 5.1, HP-UX 11, IRIX 6.5, Solaris 10, mingw, MSVC 14.

Portability problems fixed by Gnulib module vasprintf-posix:

  * This function does not support size specifiers as in C99 (hh, ll, j, t, z) on some platforms: Cygwin 1.5.24.

  * printf "%f", "%e", "%g" of Infinity and NaN yields an incorrect result on some platforms: Solaris 11.0.

  * This function does not support the a and A directives on some platforms: glibc-2.3.6, Mac OS X 10.5, NetBSD 9.0, OpenBSD 4.0, Solaris 11.4, Cygwin 1.5.x.

  * This function does not support the F directive on some platforms: NetBSD 3.0, Cygwin 1.5.x.

  * This function does not support the ls directive on some platforms: OpenBSD 4.0, Cygwin 1.5.x, Haiku.

  * This function does not support precisions in the ls directive correctly on some platforms: Solaris 11.4.

  * This function does not support format directives that access arguments in an arbitrary order, such as "%2$s", on some platforms: NetBSD 3.0.

  * This function doesn't support the ' flag on some platforms: NetBSD 3.0, Cygwin 1.5.24.

  * This function does not round the argument of the a directive correctly on some platforms: Mac OS X 10.12, FreeBSD 13.0.

  * printf "%010f" of NaN and Infinity yields an incorrect result (padded with zeroes) on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, Solaris 11.0, Cygwin 1.5.x.

  * This function can crash in out-of-memory conditions on some platforms: FreeBSD 13.0, NetBSD 5.0.

Portability problems not fixed by Gnulib:

  * The %m directive is not portable, use %s mapped to an argument of strerror(errno) (or a version of strerror_r) instead.