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-rw-r--r--progs/tty_settings.c104
1 files changed, 104 insertions, 0 deletions
diff --git a/progs/tty_settings.c b/progs/tty_settings.c
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+++ b/progs/tty_settings.c
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+/****************************************************************************
+ * Copyright (c) 2016,2017 Free Software Foundation, Inc. *
+ * *
+ * Permission is hereby granted, free of charge, to any person obtaining a *
+ * copy of this software and associated documentation files (the *
+ * "Software"), to deal in the Software without restriction, including *
+ * without limitation the rights to use, copy, modify, merge, publish, *
+ * distribute, distribute with modifications, sublicense, and/or sell *
+ * copies of the Software, and to permit persons to whom the Software is *
+ * furnished to do so, subject to the following conditions: *
+ * *
+ * The above copyright notice and this permission notice shall be included *
+ * in all copies or substantial portions of the Software. *
+ * *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS *
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF *
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. *
+ * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR *
+ * THE USE OR OTHER DEALINGS IN THE SOFTWARE. *
+ * *
+ * Except as contained in this notice, the name(s) of the above copyright *
+ * holders shall not be used in advertising or otherwise to promote the *
+ * sale, use or other dealings in this Software without prior written *
+ * authorization. *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Author: Thomas E. Dickey *
+ ****************************************************************************/
+
+#define USE_LIBTINFO
+#include <tty_settings.h>
+
+#include <fcntl.h>
+
+MODULE_ID("$Id: tty_settings.c,v 1.5 2017/10/07 20:55:57 tom Exp $")
+
+static int my_fd;
+static TTY original_settings;
+static bool can_restore = FALSE;
+
+static void
+failed(const char *msg)
+{
+ int code = errno;
+
+ (void) fprintf(stderr, "%s: %s: %s\n", _nc_progname, msg, strerror(code));
+ restore_tty_settings();
+ (void) fprintf(stderr, "\n");
+ ExitProgram(ErrSystem(code));
+ /* NOTREACHED */
+}
+
+static bool
+get_tty_settings(int fd, TTY * tty_settings)
+{
+ bool success = TRUE;
+ my_fd = fd;
+ if (fd < 0 || GET_TTY(my_fd, tty_settings) < 0) {
+ success = FALSE;
+ }
+ return success;
+}
+
+/*
+ * Open a file descriptor on the current terminal, to obtain its settings.
+ * stderr is less likely to be redirected than stdout; try that first.
+ */
+int
+save_tty_settings(TTY * tty_settings, bool need_tty)
+{
+ if (!get_tty_settings(STDERR_FILENO, tty_settings) &&
+ !get_tty_settings(STDOUT_FILENO, tty_settings) &&
+ !get_tty_settings(STDIN_FILENO, tty_settings) &&
+ !get_tty_settings(open("/dev/tty", O_RDWR), tty_settings)) {
+ if (need_tty) {
+ failed("terminal attributes");
+ } else {
+ my_fd = fileno(stdout);
+ }
+ } else {
+ can_restore = TRUE;
+ original_settings = *tty_settings;
+ }
+ return my_fd;
+}
+
+void
+restore_tty_settings(void)
+{
+ if (can_restore)
+ SET_TTY(my_fd, &original_settings);
+}
+
+/* Set the modes if they've changed. */
+void
+update_tty_settings(TTY * old_settings, TTY * new_settings)
+{
+ if (memcmp(new_settings, old_settings, sizeof(TTY))) {
+ SET_TTY(my_fd, new_settings);
+ }
+}