win32: changes to console mode handling

Add the environment variable BB_TERMINAL_MODE as a more general way
of controlling console/terminal mode setting.  The default remains
unchanged:  use virtual terminal mode for output if possible but
fall back to the console API with emulated ANSI escape sequences.

Currently valid settings are:

   0  Force use of console mode
   1  Force use of virtual terminal mode for output
   5  Prefer virtual terminal mode for output, fall back to console

Other values won't do anything useful until code elsewhere has been
updated.

BB_SKIP_ANSI_EMULATION remains available for backwards compatibility.
If both variables are set BB_TERMINAL_MODE takes precedence.

1 files changed, 4 insertions, 0 deletions

diff --git a/libbb/messages.c b/libbb/messages.c
index e35bf8c6b..3c9d8683a 100644
--- a/libbb/messages.c
+++ b/libbb/messages.c
@@ -36,10 +36,14 @@ const char bb_busybox_exec_path[] ALIGN1 = CONFIG_BUSYBOX_EXEC_PATH;
  * BB_GLOBBING and BB_UMASK are excluded because users shouln't be
  * messing with them; BB_ALT_BUFFER and BB_FIX_BACKSLASH are excluded
  * because they only affect particular applets, not the shell itself.
+ *
+ * If you change any of these you should also update the definitions in
+ * include/libbb.h.
  */
 const char bbvar[] ALIGN1 =
                 "BB_OVERRIDE_APPLETS\0" \
                 "BB_SKIP_ANSI_EMULATION\0" \
+                "BB_TERMINAL_MODE\0" \
                 "BB_SYSTEMROOT\0";
 #endif
 const char bb_default_login_shell[] ALIGN1 = LIBBB_DEFAULT_LOGIN_SHELL;