1 /**************************************************************************** 2 * Copyright (c) 2016,2017 Free Software Foundation, Inc. * 3 * * 4 * Permission is hereby granted, free of charge, to any person obtaining a * 5 * copy of this software and associated documentation files (the * 6 * "Software"), to deal in the Software without restriction, including * 7 * without limitation the rights to use, copy, modify, merge, publish, * 8 * distribute, distribute with modifications, sublicense, and/or sell * 9 * copies of the Software, and to permit persons to whom the Software is * 10 * furnished to do so, subject to the following conditions: * 11 * * 12 * The above copyright notice and this permission notice shall be included * 13 * in all copies or substantial portions of the Software. * 14 * * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * 16 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * 17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * 18 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, * 19 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR * 20 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR * 21 * THE USE OR OTHER DEALINGS IN THE SOFTWARE. * 22 * * 23 * Except as contained in this notice, the name(s) of the above copyright * 24 * holders shall not be used in advertising or otherwise to promote the * 25 * sale, use or other dealings in this Software without prior written * 26 * authorization. * 27 ****************************************************************************/ 28 29 /**************************************************************************** 30 * Author: Thomas E. Dickey * 31 ****************************************************************************/ 32 33 #define USE_LIBTINFO 34 #include <tty_settings.h> 35 36 #include <fcntl.h> 37 38 MODULE_ID("$Id: tty_settings.c,v 1.5 2017/10/07 20:55:57 tom Exp $") 39 40 static int my_fd; 41 static TTY original_settings; 42 static bool can_restore = FALSE; 43 44 static void 45 failed(const char *msg) 46 { 47 int code = errno; 48 49 (void) fprintf(stderr, "%s: %s: %s\n", _nc_progname, msg, strerror(code)); 50 restore_tty_settings(); 51 (void) fprintf(stderr, "\n"); 52 ExitProgram(ErrSystem(code)); 53 /* NOTREACHED */ 54 } 55 56 static bool 57 get_tty_settings(int fd, TTY * tty_settings) 58 { 59 bool success = TRUE; 60 my_fd = fd; 61 if (fd < 0 || GET_TTY(my_fd, tty_settings) < 0) { 62 success = FALSE; 63 } 64 return success; 65 } 66 67 /* 68 * Open a file descriptor on the current terminal, to obtain its settings. 69 * stderr is less likely to be redirected than stdout; try that first. 70 */ 71 int 72 save_tty_settings(TTY * tty_settings, bool need_tty) 73 { 74 if (!get_tty_settings(STDERR_FILENO, tty_settings) && 75 !get_tty_settings(STDOUT_FILENO, tty_settings) && 76 !get_tty_settings(STDIN_FILENO, tty_settings) && 77 !get_tty_settings(open("/dev/tty", O_RDWR), tty_settings)) { 78 if (need_tty) { 79 failed("terminal attributes"); 80 } else { 81 my_fd = fileno(stdout); 82 } 83 } else { 84 can_restore = TRUE; 85 original_settings = *tty_settings; 86 } 87 return my_fd; 88 } 89 90 void 91 restore_tty_settings(void) 92 { 93 if (can_restore) 94 SET_TTY(my_fd, &original_settings); 95 } 96 97 /* Set the modes if they've changed. */ 98 void 99 update_tty_settings(TTY * old_settings, TTY * new_settings) 100 { 101 if (memcmp(new_settings, old_settings, sizeof(TTY))) { 102 SET_TTY(my_fd, new_settings); 103 } 104 } 105