isatty: Make it return true in Cygwin consoles on native Windows. * lib/isatty.c: Include <string.h>. (GetProcAddress): New macro. (GetNamedPipeClientProcessIdFuncType): New type. (GetNamedPipeClientProcessIdFunc): New variable. (QueryFullProcessImageNameFuncType): New type. (QueryFullProcessImageNameFunc): New variable. (initialized): New variable. (initialize): New function. (IsCygwinConsoleHandle): New function. (isatty): Invoke it. * doc/posix-functions/isatty.texi: Mention the issue.

Description:
ptsname() function: Determine name of the slave side of a pseudo-terminal.

Files:
lib/ptsname.c
m4/ptsname.m4

Depends-on:
stdlib
extensions
ptsname_r       [test $HAVE_PTSNAME = 0]

configure.ac:
gl_FUNC_PTSNAME
if test $HAVE_PTSNAME = 0 || test $REPLACE_PTSNAME = 1; then
  AC_LIBOBJ([ptsname])
  gl_PREREQ_PTSNAME
fi
gl_STDLIB_MODULE_INDICATOR([ptsname])

Makefile.am:

Include:
<stdlib.h>

License:
LGPLv2+

Maintainer:
all