dnl CF_FUNC_TGETENT version: 18 updated: 2011/08/09 21:06:37
dnl ---------------
dnl Check for tgetent function in termcap library.  If we cannot find this,
dnl we'll use the $LINES and $COLUMNS environment variables to pass screen
dnl size information to subprocesses.  (We cannot use terminfo's compatibility
dnl function, since it cannot provide the termcap-format data).
dnl
dnl If the --disable-full-tgetent option is given, we'll settle for the first
dnl tgetent function we find.  Since the search list in that case does not
dnl include the termcap library, that allows us to default to terminfo.
AC_DEFUN([CF_FUNC_TGETENT],
[
# compute a reasonable value for $TERM to give tgetent(), since we may be
# running in 'screen', which sets $TERMCAP to a specific entry that is not
# necessarily in /etc/termcap - unsetenv is not portable, so we cannot simply
# discard $TERMCAP.
cf_TERMVAR=vt100
if test -n "$TERMCAP"
then
	cf_TERMCAP=`echo "$TERMCAP" | tr '\n' ' ' | sed -e 's/^..|//' -e 's/|.*//'`
	case "$cf_TERMCAP" in #(vi
	screen*.*) #(vi
		;;
	*)
		cf_TERMVAR="$cf_TERMCAP"
		;;
	esac
fi
test -z "$cf_TERMVAR" && cf_TERMVAR=vt100

AC_MSG_CHECKING(if we want full tgetent function)
CF_ARG_DISABLE(full-tgetent,
	[  --disable-full-tgetent  disable check for full tgetent function],
	cf_full_tgetent=no,
	cf_full_tgetent=yes,yes)
AC_MSG_RESULT($cf_full_tgetent)

if test "$cf_full_tgetent" = yes ; then
	cf_test_message="full tgetent"
else
	cf_test_message="tgetent"
fi

AC_CACHE_CHECK(for $cf_test_message function,cf_cv_lib_tgetent,[
cf_save_LIBS="$LIBS"
cf_cv_lib_tgetent=no
if test "$cf_full_tgetent" = yes ; then
	cf_TERMLIB="otermcap termcap termlib ncurses curses"
	cf_TERMTST="buffer[[0]] == 0"
else
	cf_TERMLIB="termlib ncurses curses"
	cf_TERMTST="0"
fi
for cf_termlib in '' $cf_TERMLIB ; do
	LIBS="$cf_save_LIBS"
	test -n "$cf_termlib" && CF_ADD_LIB($cf_termlib)
	AC_TRY_RUN([
/* terminfo implementations ignore the buffer argument, making it useless for
 * the xterm application, which uses this information to make a new TERMCAP
 * environment variable.
 */
int main()
{
	char buffer[1024];
	buffer[0] = 0;
	tgetent(buffer, "$cf_TERMVAR");
	${cf_cv_main_return:-return} ($cf_TERMTST); }],
	[echo "yes, there is a termcap/tgetent in $cf_termlib" 1>&AC_FD_CC
	 if test -n "$cf_termlib" ; then
	 	cf_cv_lib_tgetent="-l$cf_termlib"
	 else
	 	cf_cv_lib_tgetent=yes
	 fi
	 break],
	[echo "no, there is no termcap/tgetent in $cf_termlib" 1>&AC_FD_CC],
	[echo "cross-compiling, cannot verify if a termcap/tgetent is present in $cf_termlib" 1>&AC_FD_CC])
done
LIBS="$cf_save_LIBS"
])

# If we found a working tgetent(), set LIBS and check for termcap.h.
# (LIBS cannot be set inside AC_CACHE_CHECK; the commands there should
# not have side effects other than setting the cache variable, because
# they are not executed when a cached value exists.)
if test "x$cf_cv_lib_tgetent" != xno ; then
	test "x$cf_cv_lib_tgetent" != xyes && CF_ADD_LIBS($cf_cv_lib_tgetent)
	AC_DEFINE(USE_TERMCAP)
	if test "$cf_full_tgetent" = no ; then
		AC_TRY_COMPILE([
#include <termcap.h>],[
#ifdef NCURSES_VERSION
make an error
#endif],[AC_DEFINE(HAVE_TERMCAP_H)])
	else
		AC_CHECK_HEADERS(termcap.h)
	fi
else
        # If we didn't find a tgetent() that supports the buffer
        # argument, look again to see whether we can find even
        # a crippled one.  A crippled tgetent() is still useful to
        # validate values for the TERM environment variable given to
        # child processes.
	AC_CACHE_CHECK(for partial tgetent function,cf_cv_lib_part_tgetent,[
	cf_cv_lib_part_tgetent=no
	for cf_termlib in $cf_TERMLIB ; do
		LIBS="$cf_save_LIBS -l$cf_termlib"
		AC_TRY_LINK([],[tgetent(0, "$cf_TERMVAR")],
			[echo "there is a terminfo/tgetent in $cf_termlib" 1>&AC_FD_CC
			 cf_cv_lib_part_tgetent="-l$cf_termlib"
			 break])
	done
	LIBS="$cf_save_LIBS"
	])

	if test "$cf_cv_lib_part_tgetent" != no ; then
		CF_ADD_LIBS($cf_cv_lib_part_tgetent)
		AC_CHECK_HEADERS(termcap.h)

                # If this is linking against ncurses, we'll trigger the
                # ifdef in resize.c that turns the termcap stuff back off.
		AC_DEFINE(USE_TERMINFO)
	fi
fi
])dnl
