8.1093 twalk

POSIX specification:
http://www.opengroup.org/onlinepubs/9699919799/functions/twalk.html

Gnulib module: tsearch

Portability problems fixed by Gnulib:

• This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 9, BeOS.

Portability problems not fixed by Gnulib: