+dnl CF_FUNC_GETTTYNAM version: 1 updated: 2021/12/04 18:29:47
+dnl -----------------
+dnl Check if the 4.3BSD function getttyname exists, as well as if <ttyent.h>
+dnl defines the _PATH_TTYS symbol. If the corresponding file exists, but the
+dnl other checks fail, just define HAVE_PATH_TTYS.
+AC_DEFUN([CF_FUNC_GETTTYNAM],[
+AC_CACHE_CHECK(if _PATH_TTYS is defined in ttyent.h,cf_cv_PATH_TTYS,[
+AC_TRY_COMPILE([
+#include <stdio.h>
+#include <ttyent.h>],[
+FILE *fp = fopen(_PATH_TTYS, "r"); (void)fp],
+ [cf_cv_PATH_TTYS=yes],
+ [cf_cv_PATH_TTYS=no])])
+
+if test $cf_cv_PATH_TTYS = no
+then
+ for cf_ttys in /etc/ttytype /etc/ttys
+ do
+ if test -f $cf_ttys
+ then
+ cf_cv_PATH_TTYS=maybe
+ AC_DEFINE(_PATH_TTYS,$cf_ttys,[define to pathname of file containing mapping from tty name to terminal type])
+ break
+ fi
+ done
+fi
+
+if test $cf_cv_PATH_TTYS != no
+then
+ AC_CACHE_CHECK(if _PATH_TTYS file exists,cf_cv_have_PATH_TTYS,[
+ AC_TRY_RUN([
+#include <stdio.h>
+#include <ttyent.h>
+int main(void) {
+ FILE *fp = fopen(_PATH_TTYS, "r");
+ ${cf_cv_main_return:-return} (fp == 0);
+}],
+ [cf_cv_have_PATH_TTYS=yes],
+ [cf_cv_have_PATH_TTYS=no],
+ [cf_cv_have_PATH_TTYS=unknown])])
+ test "$cf_cv_have_PATH_TTYS" = no && cf_cv_PATH_TTYS=no
+fi
+
+if test $cf_cv_PATH_TTYS != no
+then
+ AC_DEFINE(HAVE_PATH_TTYS,1,[define to 1 if system can map tty name to terminal type])
+ AC_CACHE_CHECK(for getttynam,cf_cv_func_getttynam,[
+ AC_TRY_LINK([#include <ttyent.h>],
+ [struct ttyent *fp = getttynam("/dev/tty"); (void)fp],
+ [cf_cv_func_getttynam=yes],
+ [cf_cv_func_getttynam=no])])
+ test "$cf_cv_func_getttynam" = yes && AC_DEFINE(HAVE_GETTTYNAM)
+fi
+])dnl
+dnl ---------------------------------------------------------------------------