1 /* 2 * $Id: ttysize.c,v 1.3 2022/04/03 22:38:16 tom Exp $ 3 * 4 * ttysize.c -- obtain terminal-size for dialog 5 * 6 * Copyright 2018-2019,2022 Thomas E. Dickey 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU Lesser General Public License, version 2.1 10 * as published by the Free Software Foundation. 11 * 12 * This program is distributed in the hope that it will be useful, but 13 * WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with this program; if not, write to 19 * Free Software Foundation, Inc. 20 * 51 Franklin St., Fifth Floor 21 * Boston, MA 02110, USA. 22 * 23 * An earlier version of this program lists as authors 24 * Savio Lam (lam836@cs.cuhk.hk) 25 */ 26 27 #include <dlg_internals.h> 28 29 /* 30 * This is based on work I did for ncurses in 1997, and improved/extended for 31 * other terminal-based programs. The comments are from my original version -TD 32 */ 33 34 #ifdef HAVE_TERMIOS_H 35 #include <termios.h> 36 #endif 37 38 #ifdef HAVE_SYS_IOCTL_H 39 # include <sys/ioctl.h> 40 #endif 41 42 #ifdef NEED_PTEM_H 43 /* On SCO, they neglected to define struct winsize in termios.h -- it's only 44 * in termio.h and ptem.h (the former conflicts with other definitions). 45 */ 46 # include <sys/stream.h> 47 # include <sys/ptem.h> 48 #endif 49 50 /* 51 * SCO defines TIOCGSIZE and the corresponding struct. Other systems (SunOS, 52 * Solaris, IRIX) define TIOCGWINSZ and struct winsize. 53 */ 54 #if defined(TIOCGSIZE) 55 # define IOCTL_WINSIZE TIOCGSIZE 56 # define STRUCT_WINSIZE struct ttysize 57 # define WINSIZE_ROWS(n) (int)n.ts_lines 58 # define WINSIZE_COLS(n) (int)n.ts_cols 59 #elif defined(TIOCGWINSZ) 60 # define IOCTL_WINSIZE TIOCGWINSZ 61 # define STRUCT_WINSIZE struct winsize 62 # define WINSIZE_ROWS(n) (int)n.ws_row 63 # define WINSIZE_COLS(n) (int)n.ws_col 64 #else 65 # undef HAVE_SIZECHANGE 66 #endif 67 68 int 69 dlg_ttysize(int fd, int *high, int *wide) 70 { 71 int rc = -1; 72 #ifdef HAVE_SIZECHANGE 73 if (isatty(fd)) { 74 STRUCT_WINSIZE size; 75 76 if (ioctl(fd, IOCTL_WINSIZE, &size) >= 0) { 77 *high = WINSIZE_ROWS(size); 78 *wide = WINSIZE_COLS(size); 79 rc = 0; 80 } 81 } 82 #else 83 *high = 24; 84 *wide = 80; 85 #endif /* HAVE_SIZECHANGE */ 86 return rc; 87 } 88