1 /*        $NetBSD: setterm.c,v 1.72 2024/05/17 23:32:50 uwe Exp $     */
2 
3 /*
4  * Copyright (c) 1981, 1993, 1994
5  *        The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)setterm.c   8.8 (Berkeley) 10/25/94";
36 #else
37 __RCSID("$NetBSD: setterm.c,v 1.72 2024/05/17 23:32:50 uwe Exp $");
38 #endif
39 #endif /* not lint */
40 
41 #include <stdlib.h>
42 #include <string.h>
43 #include <termios.h>
44 #include <unistd.h>
45 
46 #include "curses.h"
47 #include "curses_private.h"
48 
49 static int does_esc_m(const char *cap);
50 static int does_ctrl_o(const char *exit_cap, const char *acs_cap);
51 
52 attr_t     __mask_op, __mask_me, __mask_ue, __mask_se;
53 
54 int
setterm(const char * type)55 setterm(const char *type)
56 {
57 
58           return _cursesi_setterm(type, _cursesi_screen);
59 }
60 
61 int
_cursesi_setterm(const char * type,SCREEN * screen)62 _cursesi_setterm(const char *type, SCREEN *screen)
63 {
64           int unknown, r;
65           char *p;
66 
67           if (type[0] == '\0')
68                     type = "xx";
69           unknown = 0;
70           if (screen->term)
71                     del_curterm(screen->term);
72           (void)ti_setupterm(&screen->term, type, fileno(screen->outfd), &r);
73           if (screen->term == NULL) {
74                     unknown++;
75                     (void)ti_setupterm(&screen->term, "dumb",
76                         fileno(screen->outfd), &r);
77                     /* No dumb term? We can't continue */
78                     if (screen->term == NULL)
79                               return ERR;
80           }
81           __CTRACE(__CTRACE_INIT, "setterm: tty = %s\n", type);
82 
83           /* lines and cols will have been setup correctly by ti_setupterm(3). */
84           screen->LINES = t_lines(screen->term);
85           screen->COLS = t_columns(screen->term);
86 
87           if (screen->filtered) {
88                     /* Disable use of clear, cud, cud1, cup, cuu1 and vpa. */
89                     screen->term->strs[TICODE_clear] = NULL;
90                     screen->term->strs[TICODE_cud] = NULL;
91                     screen->term->strs[TICODE_cud1] = NULL;
92                     screen->term->strs[TICODE_cup] = NULL;
93                     screen->term->strs[TICODE_cuu] = NULL;
94                     screen->term->strs[TICODE_cuu1] = NULL;
95                     screen->term->strs[TICODE_vpa] = NULL;
96                     /* Set the value of the home string to the value of
97                      * the cr string. */
98                     screen->term->strs[TICODE_home] = screen->term->strs[TICODE_cr];
99                     /* Set lines equal to 1. */
100                     screen->LINES = 1;
101                     t_lines(screen->term) = 1;
102           }
103           __CTRACE(__CTRACE_INIT, "setterm: filtered %d\n", screen->filtered);
104 
105           if ((p = getenv("ESCDELAY")) != NULL)
106                     screen->ESCDELAY = (int)strtol(p, NULL, 0);
107           else
108                     screen->ESCDELAY = ESCDELAY_DEFAULT;
109           if ((p = getenv("TABSIZE")) != NULL)
110                     screen->TABSIZE = (int)strtol(p, NULL, 0);
111           else if (t_init_tabs(screen->term) >= 0)
112                     screen->TABSIZE = (int)t_init_tabs(screen->term);
113           else
114                     screen->TABSIZE = TABSIZE_DEFAULT;
115           /*
116            * Want cols > 4, otherwise things will fail.
117            */
118           if (screen->COLS <= 4)
119                     return ERR;
120 
121           LINES = screen->LINES;
122           COLS = screen->COLS;
123           ESCDELAY = screen->ESCDELAY;
124           TABSIZE = screen->TABSIZE;
125 
126           __CTRACE(__CTRACE_INIT,
127               "setterm: LINES = %d, COLS = %d, TABSIZE = %d\n",
128               LINES, COLS, TABSIZE);
129 
130           /*
131            * set the pad char, only take the first char of the pc capability
132            * as this is all we can use.
133            */
134           screen->padchar = t_pad_char(screen->term) ?
135               t_pad_char(screen->term)[0] : 0;
136 
137           /* If no scrolling commands, no quick change. */
138           screen->noqch =
139               (t_change_scroll_region(screen->term) == NULL ||
140                     t_cursor_home(screen->term) == NULL ||
141                     (t_parm_index(screen->term) == NULL &&
142                         t_scroll_forward(screen->term) == NULL) ||
143                     (t_parm_rindex(screen->term) == NULL &&
144                         t_scroll_reverse(screen->term) == NULL)) &&
145               ((t_parm_insert_line(screen->term) == NULL &&
146                     t_insert_line(screen->term) == NULL) ||
147                     (t_parm_delete_line(screen->term) == NULL &&
148                         t_delete_line(screen->term) == NULL));
149 
150           /*
151            * Precalculate conflict info for color/attribute end commands.
152            */
153 #ifndef HAVE_WCHAR
154           screen->mask_op = __ATTRIBUTES & ~__COLOR;
155 #else
156           screen->mask_op = WA_ATTRIBUTES & ~__COLOR;
157 #endif /* HAVE_WCHAR */
158 
159           const char *t_op = t_orig_pair(screen->term);
160           const char *t_esm = t_exit_standout_mode(screen->term);
161           const char *t_eum = t_exit_underline_mode(screen->term);
162           const char *t_eam = t_exit_attribute_mode(screen->term);
163 
164           if (t_op != NULL) {
165                     if (does_esc_m(t_op))
166                               screen->mask_op &=
167                                   ~(__STANDOUT | __UNDERSCORE | __TERMATTR);
168                     else {
169                               if (t_esm != NULL && !strcmp(t_op, t_esm))
170                                         screen->mask_op &= ~__STANDOUT;
171 
172                               if (t_eum != NULL && !strcmp(t_op, t_eum))
173                                         screen->mask_op &= ~__UNDERSCORE;
174 
175                               if (t_eam != NULL && !strcmp(t_op, t_eam))
176                                         screen->mask_op &= ~__TERMATTR;
177                     }
178           }
179           /*
180            * Assume that "me" turns off all attributes apart from ACS.
181            * It might turn off ACS, so check for that.
182            */
183           if (t_exit_attribute_mode(screen->term) != NULL &&
184               t_exit_alt_charset_mode(screen->term) != NULL &&
185               does_ctrl_o(t_exit_attribute_mode(screen->term),
186               t_exit_alt_charset_mode(screen->term)))
187                     screen->mask_me = 0;
188           else
189                     screen->mask_me = __ALTCHARSET;
190 
191           /* Check what turning off the attributes also turns off */
192 #ifndef HAVE_WCHAR
193           screen->mask_ue = __ATTRIBUTES & ~__UNDERSCORE;
194 #else
195           screen->mask_ue = WA_ATTRIBUTES & ~__UNDERSCORE;
196 #endif /* HAVE_WCHAR */
197           if (t_eum != NULL) {
198                     if (does_esc_m(t_eum))
199                               screen->mask_ue &=
200                                   ~(__STANDOUT | __TERMATTR | __COLOR);
201                     else {
202                               if (t_esm && !strcmp(t_eum, t_esm))
203                                         screen->mask_ue &= ~__STANDOUT;
204 
205                               if (t_eam != NULL && !strcmp(t_eum, t_eam))
206                                         screen->mask_ue &= ~__TERMATTR;
207 
208                               if (t_op != NULL && !strcmp(t_eum, t_op))
209                                         screen->mask_ue &= ~__COLOR;
210                     }
211           }
212 #ifndef HAVE_WCHAR
213           screen->mask_se = __ATTRIBUTES & ~__STANDOUT;
214 #else
215           screen->mask_se = WA_ATTRIBUTES & ~__STANDOUT;
216 #endif /* HAVE_WCHAR */
217           if (t_esm != NULL) {
218                     if (does_esc_m(t_esm))
219                               screen->mask_se &=
220                                   ~(__UNDERSCORE | __TERMATTR | __COLOR);
221                     else {
222                               if (t_eum != NULL && !strcmp(t_esm, t_eum))
223                                         screen->mask_se &= ~__UNDERSCORE;
224 
225                               if (t_eam != NULL && !strcmp(t_esm, t_eam))
226                                         screen->mask_se &= ~__TERMATTR;
227 
228                               if (t_op != NULL && !strcmp(t_esm, t_op))
229                                         screen->mask_se &= ~__COLOR;
230                     }
231           }
232 
233           return unknown ? ERR : OK;
234 }
235 
236 /*
237  * _cursesi_resetterm --
238  *  Copy the terminal instance data for the given screen to the global
239  *  variables.
240  */
241 void
_cursesi_resetterm(SCREEN * screen)242 _cursesi_resetterm(SCREEN *screen)
243 {
244 
245           LINES = screen->LINES;
246           COLS = screen->COLS;
247           ESCDELAY = screen->ESCDELAY;
248           TABSIZE = screen->TABSIZE;
249           __GT = screen->GT;
250 
251           __noqch = screen->noqch;
252           __mask_op = screen->mask_op;
253           __mask_me = screen->mask_me;
254           __mask_ue = screen->mask_ue;
255           __mask_se = screen->mask_se;
256 
257           set_curterm(screen->term);
258 }
259 
260 /*
261  * does_esc_m --
262  * A hack for xterm-like terminals where "\E[m" or "\E[0m" will turn off
263  * other attributes, so we check for this in the capability passed to us.
264  * Note that we can't just do simple string comparison, as the capability
265  * may contain multiple, ';' separated sequence parts.
266  */
267 static int
does_esc_m(const char * cap)268 does_esc_m(const char *cap)
269 {
270 #define WAITING 0
271 #define PARSING 1
272 #define NUMBER 2
273 #define FOUND 4
274           const char *capptr;
275           int seq;
276 
277           __CTRACE(__CTRACE_INIT, "does_esc_m: Checking %s\n", cap);
278           /* Is it just "\E[m" or "\E[0m"? */
279           if (!strcmp(cap, "\x1b[m") || !strcmp(cap, "\x1b[0m"))
280                     return 1;
281 
282           /* Does it contain a "\E[...m" sequence? */
283           if (strlen(cap) < 4)
284                     return 0;
285           capptr = cap;
286           seq = WAITING;
287           while (*capptr != 0) {
288                     switch (seq) {
289                     /* Start of sequence */
290                     case WAITING:
291                               if (!strncmp(capptr, "\x1b[", 2)) {
292                                         capptr+=2;
293                                         if (*capptr == 'm')
294                                                   return 1;
295                                         else {
296                                                   seq=PARSING;
297                                                   continue;
298                                         }
299                               }
300                               break;
301                     /* Looking for '0' */
302                     case PARSING:
303                               if (*capptr == '0')
304                                         seq=FOUND;
305                               else if (*capptr > '0' && *capptr <= '9')
306                                         seq=NUMBER;
307                               else if (*capptr != ';')
308                                         seq=WAITING;
309                               break;
310                     /* Some other number */
311                     case NUMBER:
312                               if (*capptr == ';')
313                                         seq=PARSING;
314                               else if (!(*capptr >= '0' && *capptr <= '9'))
315                                         seq=WAITING;
316                               break;
317                     /* Found a '0' */
318                     case FOUND:
319                               if (*capptr == 'm')
320                                         return 1;
321                               else if (!((*capptr >= '0' && *capptr <= '9') ||
322                                   *capptr == ';'))
323                                         seq=WAITING;
324                               break;
325                     default:
326                               break;
327                     }
328                     capptr++;
329           }
330           return 0;
331 }
332 
333 /*
334  * capdup_nodelay --
335  * A helper for does_ctrl_o below that creates a copy of the given
336  * capability with delay specifications dropped.
337  */
338 static char *
capdup_nodelay(const char * src)339 capdup_nodelay(const char *src)
340 {
341           char *clean, *dst;
342 
343           dst = clean = malloc(strlen(src) + 1);
344           if (__predict_false(clean == NULL))
345                     return NULL;
346 
347           while (*src != '\0') {
348                     if (src[0] == '$' && src[1] == '<') {
349                               const char *end = strchr(src + 2, '>');
350                               if (__predict_true(end != NULL)) {
351                                         src = end + 1;
352                                         continue;
353                               }
354                     }
355                     *dst++ = *src++;
356           }
357 
358           *dst = '\0';
359           return clean;
360 }
361 
362 /*
363  * does_ctrl_o --
364  * A hack for vt100/xterm-like terminals where the "me" capability also
365  * unsets acs.
366  */
367 static int
does_ctrl_o(const char * exit_cap,const char * acs_cap)368 does_ctrl_o(const char *exit_cap, const char *acs_cap)
369 {
370           char *eptr, *aptr;
371           int res;
372 
373           __CTRACE(__CTRACE_INIT, "does_ctrl_o: Testing %s for %s\n",
374               exit_cap, acs_cap);
375 
376           eptr = capdup_nodelay(exit_cap);
377           if (__predict_false(eptr == NULL))
378                     return 0;
379 
380           aptr = capdup_nodelay(acs_cap);
381           if (__predict_false(aptr == NULL)) {
382                     free(eptr);
383                     return 0;
384           }
385 
386           res = strstr(eptr, aptr) != NULL;
387 
388           free(eptr);
389           free(aptr);
390           return res;
391 }
392 
393 /*
394  * set_tabsize --
395  *   Sets the tabsize for the current screen.
396  */
397 int
set_tabsize(int tabsize)398 set_tabsize(int tabsize)
399 {
400 
401           if (_cursesi_screen == NULL)
402                     return ERR;
403           _cursesi_screen->TABSIZE = tabsize;
404           TABSIZE = tabsize;
405           return OK;
406 }
407