tcgetsid
========

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

Gnulib module: tcgetsid

Portability problems fixed by Gnulib:

     This function is missing on some platforms: MacOS X 10.3, FreeBSD 6.0, OpenBSD 4.5, Cygwin, mingw, Interix 3.5, BeOS.

Portability problems not fixed by Gnulib:

  * This function always fails on some platforms: FreeBSD 6.0, Cygwin, mingw, Interix 3.5, BeOS.