1 /**************************************************************************** 2 * Copyright 2020 Thomas E. Dickey * 3 * Copyright 2016,2017 Free Software Foundation, Inc. * 4 * * 5 * Permission is hereby granted, free of charge, to any person obtaining a * 6 * copy of this software and associated documentation files (the * 7 * "Software"), to deal in the Software without restriction, including * 8 * without limitation the rights to use, copy, modify, merge, publish, * 9 * distribute, distribute with modifications, sublicense, and/or sell * 10 * copies of the Software, and to permit persons to whom the Software is * 11 * furnished to do so, subject to the following conditions: * 12 * * 13 * The above copyright notice and this permission notice shall be included * 14 * in all copies or substantial portions of the Software. * 15 * * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * 17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * 18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * 19 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, * 20 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR * 21 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR * 22 * THE USE OR OTHER DEALINGS IN THE SOFTWARE. * 23 * * 24 * Except as contained in this notice, the name(s) of the above copyright * 25 * holders shall not be used in advertising or otherwise to promote the * 26 * sale, use or other dealings in this Software without prior written * 27 * authorization. * 28 ****************************************************************************/ 29 30 /**************************************************************************** 31 * Author: Thomas E. Dickey * 32 ****************************************************************************/ 33 34 #define USE_LIBTINFO 35 #include <tty_settings.h> 36 37 #include <fcntl.h> 38 39 MODULE_ID("$Id: tty_settings.c,v 1.6 2020/02/02 23:34:34 tom Exp $") 40 41 static int my_fd; 42 static TTY original_settings; 43 static bool can_restore = FALSE; 44 45 static void 46 failed(const char *msg) 47 { 48 int code = errno; 49 50 (void) fprintf(stderr, "%s: %s: %s\n", _nc_progname, msg, strerror(code)); 51 restore_tty_settings(); 52 (void) fprintf(stderr, "\n"); 53 ExitProgram(ErrSystem(code)); 54 /* NOTREACHED */ 55 } 56 57 static bool 58 get_tty_settings(int fd, TTY * tty_settings) 59 { 60 bool success = TRUE; 61 my_fd = fd; 62 if (fd < 0 || GET_TTY(my_fd, tty_settings) < 0) { 63 success = FALSE; 64 } 65 return success; 66 } 67 68 /* 69 * Open a file descriptor on the current terminal, to obtain its settings. 70 * stderr is less likely to be redirected than stdout; try that first. 71 */ 72 int 73 save_tty_settings(TTY * tty_settings, bool need_tty) 74 { 75 if (!get_tty_settings(STDERR_FILENO, tty_settings) && 76 !get_tty_settings(STDOUT_FILENO, tty_settings) && 77 !get_tty_settings(STDIN_FILENO, tty_settings) && 78 !get_tty_settings(open("/dev/tty", O_RDWR), tty_settings)) { 79 if (need_tty) { 80 failed("terminal attributes"); 81 } else { 82 my_fd = fileno(stdout); 83 } 84 } else { 85 can_restore = TRUE; 86 original_settings = *tty_settings; 87 } 88 return my_fd; 89 } 90 91 void 92 restore_tty_settings(void) 93 { 94 if (can_restore) 95 SET_TTY(my_fd, &original_settings); 96 } 97 98 /* Set the modes if they've changed. */ 99 void 100 update_tty_settings(TTY * old_settings, TTY * new_settings) 101 { 102 if (memcmp(new_settings, old_settings, sizeof(TTY))) { 103 SET_TTY(my_fd, new_settings); 104 } 105 } 106