1 /* $NetBSD: hack.pager.c,v 1.21 2011/09/01 07:18:50 plunky Exp $ */
2
3 /*
4 * Copyright (c) 1985, Stichting Centrum voor Wiskunde en Informatica,
5 * Amsterdam
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions are
10 * met:
11 *
12 * - Redistributions of source code must retain the above copyright notice,
13 * this list of conditions and the following disclaimer.
14 *
15 * - Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * - Neither the name of the Stichting Centrum voor Wiskunde en
20 * Informatica, nor the names of its contributors may be used to endorse or
21 * promote products derived from this software without specific prior
22 * written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
25 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
26 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
27 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
28 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
29 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
30 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
31 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
32 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
33 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
34 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 */
36
37 /*
38 * Copyright (c) 1982 Jay Fenlason <hack@gnu.org>
39 * All rights reserved.
40 *
41 * Redistribution and use in source and binary forms, with or without
42 * modification, are permitted provided that the following conditions
43 * are met:
44 * 1. Redistributions of source code must retain the above copyright
45 * notice, this list of conditions and the following disclaimer.
46 * 2. Redistributions in binary form must reproduce the above copyright
47 * notice, this list of conditions and the following disclaimer in the
48 * documentation and/or other materials provided with the distribution.
49 * 3. The name of the author may not be used to endorse or promote products
50 * derived from this software without specific prior written permission.
51 *
52 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
53 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
54 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
55 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
56 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
57 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
58 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
59 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
60 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
61 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
62 */
63
64 #include <sys/cdefs.h>
65 #ifndef lint
66 __RCSID("$NetBSD: hack.pager.c,v 1.21 2011/09/01 07:18:50 plunky Exp $");
67 #endif /* not lint */
68
69 /* This file contains the command routine dowhatis() and a pager. */
70 /*
71 * Also readmail() and doshell(), and generally the things that contact the
72 * outside world.
73 */
74
75 #include <sys/types.h>
76 #include <sys/wait.h>
77 #include <signal.h>
78 #include <stdlib.h>
79 #include <unistd.h>
80 #include "hack.h"
81 #include "extern.h"
82
83 static void intruph(int);
84 static void page_more(FILE *, int);
85 static int page_file(const char *, boolean);
86 static int child(int);
87
88 int
dowhatis(void)89 dowhatis(void)
90 {
91 FILE *fp;
92 char bufr[BUFSZ + 6];
93 char *buf = &bufr[6], *ep, q;
94
95 if (!(fp = fopen(DATAFILE, "r")))
96 pline("Cannot open data file!");
97 else {
98 pline("Specify what? ");
99 q = readchar();
100 if (q != '\t')
101 while (fgets(buf, BUFSZ, fp))
102 if (*buf == q) {
103 ep = strchr(buf, '\n');
104 if (ep)
105 *ep = 0;
106 /* else: bad data file */
107 else {
108 pline("Bad data file!");
109 (void) fclose(fp);
110 return(0);
111 }
112 /* Expand tab 'by hand' */
113 if (buf[1] == '\t') {
114 buf = bufr;
115 buf[0] = q;
116 (void) strncpy(buf + 1, " ", 7);
117 }
118 pline("%s", buf);
119 if (ep[-1] == ';') {
120 pline("More info? ");
121 if (readchar() == 'y') {
122 page_more(fp, 1); /* does fclose() */
123 return (0);
124 }
125 }
126 (void) fclose(fp); /* kopper@psuvax1 */
127 return (0);
128 }
129 pline("I've never heard of such things.");
130 (void) fclose(fp);
131 }
132 return (0);
133 }
134
135 /* make the paging of a file interruptible */
136 static int got_intrup;
137
138 static void
intruph(int n __unused)139 intruph(int n __unused)
140 {
141 got_intrup++;
142 }
143
144 /* simple pager, also used from dohelp() */
145 /* strip: nr of chars to be stripped from each line (0 or 1) */
146 static void
page_more(FILE * fp,int strip)147 page_more(FILE *fp, int strip)
148 {
149 char *bufr, *ep;
150 sig_t prevsig = signal(SIGINT, intruph);
151
152 set_pager(0);
153 bufr = alloc(CO);
154 bufr[CO - 1] = 0;
155 while (fgets(bufr, CO - 1, fp) && (!strip || *bufr == '\t') && !got_intrup) {
156 ep = strchr(bufr, '\n');
157 if (ep)
158 *ep = 0;
159 if (page_line(bufr + strip)) {
160 set_pager(2);
161 goto ret;
162 }
163 }
164 set_pager(1);
165 ret:
166 free(bufr);
167 (void) fclose(fp);
168 (void) signal(SIGINT, prevsig);
169 got_intrup = 0;
170 }
171
172 static boolean whole_screen = TRUE;
173 #define PAGMIN 12 /* minimum # of lines for page below level
174 * map */
175
176 void
set_whole_screen(void)177 set_whole_screen(void)
178 { /* called in termcap as soon as LI is known */
179 whole_screen = (LI - ROWNO - 2 <= PAGMIN || !CD);
180 }
181
182 #ifdef NEWS
183 int
readnews(void)184 readnews(void)
185 {
186 int ret;
187
188 whole_screen = TRUE; /* force a docrt(), our first */
189 ret = page_file(NEWS, TRUE);
190 set_whole_screen();
191 return (ret); /* report whether we did docrt() */
192 }
193 #endif /* NEWS */
194
195 /* mode: 0: open 1: wait+close 2: close */
196 void
set_pager(int mode)197 set_pager(int mode)
198 {
199 static boolean so;
200 if (mode == 0) {
201 if (!whole_screen) {
202 /* clear topline */
203 clrlin();
204 /* use part of screen below level map */
205 curs(1, ROWNO + 4);
206 } else {
207 cls();
208 }
209 so = flags.standout;
210 flags.standout = 1;
211 } else {
212 if (mode == 1) {
213 curs(1, LI);
214 more();
215 }
216 flags.standout = so;
217 if (whole_screen)
218 docrt();
219 else {
220 curs(1, ROWNO + 4);
221 cl_eos();
222 }
223 }
224 }
225
226 int
page_line(const char * s)227 page_line(const char *s) /* returns 1 if we should quit */
228 {
229 if (cury == LI - 1) {
230 if (!*s)
231 return (0); /* suppress blank lines at top */
232 putchar('\n');
233 cury++;
234 cmore("q\033");
235 if (morc) {
236 morc = 0;
237 return (1);
238 }
239 if (whole_screen)
240 cls();
241 else {
242 curs(1, ROWNO + 4);
243 cl_eos();
244 }
245 }
246 puts(s);
247 cury++;
248 return (0);
249 }
250
251 /*
252 * Flexible pager: feed it with a number of lines and it will decide
253 * whether these should be fed to the pager above, or displayed in a
254 * corner.
255 * Call:
256 * cornline(0, title or 0) : initialize
257 * cornline(1, text) : add text to the chain of texts
258 * cornline(2, morcs) : output everything and cleanup
259 * cornline(3, 0) : cleanup
260 */
261
262 void
cornline(int mode,const char * text)263 cornline(int mode, const char *text)
264 {
265 static struct line {
266 struct line *next_line;
267 char *line_text;
268 } *texthead, *texttail;
269 static int maxlen;
270 static int linect;
271 struct line *tl;
272
273 if (mode == 0) {
274 texthead = 0;
275 maxlen = 0;
276 linect = 0;
277 if (text) {
278 cornline(1, text); /* title */
279 cornline(1, ""); /* blank line */
280 }
281 return;
282 }
283 if (mode == 1) {
284 int len;
285
286 if (!text)
287 return; /* superfluous, just to be sure */
288 linect++;
289 len = strlen(text);
290 if (len > maxlen)
291 maxlen = len;
292 tl = alloc(len + sizeof(*tl) + 1);
293 tl->next_line = 0;
294 tl->line_text = (char *) (tl + 1);
295 (void) strcpy(tl->line_text, text);
296 if (!texthead)
297 texthead = tl;
298 else
299 texttail->next_line = tl;
300 texttail = tl;
301 return;
302 }
303 /* --- now we really do it --- */
304 if (mode == 2 && linect == 1) /* topline only */
305 pline("%s", texthead->line_text);
306 else if (mode == 2) {
307 int curline, lth;
308
309 if (flags.toplin == 1)
310 more(); /* ab@unido */
311 remember_topl();
312
313 lth = CO - maxlen - 2; /* Use full screen width */
314 if (linect < LI && lth >= 10) { /* in a corner */
315 home();
316 cl_end();
317 flags.toplin = 0;
318 curline = 1;
319 for (tl = texthead; tl; tl = tl->next_line) {
320 curs(lth, curline);
321 if (curline > 1)
322 cl_end();
323 putsym(' ');
324 putstr(tl->line_text);
325 curline++;
326 }
327 curs(lth, curline);
328 cl_end();
329 cmore(text);
330 home();
331 cl_end();
332 docorner(lth, curline - 1);
333 } else { /* feed to pager */
334 set_pager(0);
335 for (tl = texthead; tl; tl = tl->next_line) {
336 if (page_line(tl->line_text)) {
337 set_pager(2);
338 goto cleanup;
339 }
340 }
341 if (text) {
342 cgetret(text);
343 set_pager(2);
344 } else
345 set_pager(1);
346 }
347 }
348 cleanup:
349 while ((tl = texthead) != NULL) {
350 texthead = tl->next_line;
351 free(tl);
352 }
353 }
354
355 int
dohelp(void)356 dohelp(void)
357 {
358 char c;
359
360 pline("Long or short help? ");
361 while (((c = readchar()) != 'l') && (c != 's') && !strchr(quitchars, c))
362 sound_bell();
363 if (!strchr(quitchars, c))
364 (void) page_file((c == 'l') ? HELP : SHELP, FALSE);
365 return (0);
366 }
367
368 /* return: 0 - cannot open fnam; 1 - otherwise */
369 static int
page_file(const char * fnam,boolean silent)370 page_file(const char *fnam, boolean silent)
371 {
372 #ifdef DEF_PAGER /* this implies that UNIX is defined */
373 {
374 /* use external pager; this may give security problems */
375
376 int fd = open(fnam, O_RDONLY);
377
378 if (fd < 0) {
379 if (!silent)
380 pline("Cannot open %s.", fnam);
381 return (0);
382 }
383 if (child(1)) {
384
385 /*
386 * Now that child() does a setuid(getuid()) and a
387 * chdir(), we may not be able to open file fnam
388 * anymore, so make it stdin.
389 */
390 (void) close(0);
391 if (dup(fd)) {
392 if (!silent)
393 printf("Cannot open %s as stdin.\n", fnam);
394 } else {
395 execl(catmore, "page", (char *)NULL);
396 if (!silent)
397 printf("Cannot exec %s.\n", catmore);
398 }
399 exit(1);
400 }
401 (void) close(fd);
402 }
403 #else /* DEF_PAGER */
404 {
405 FILE *f; /* free after Robert Viduya */
406
407 if ((f = fopen(fnam, "r")) == (FILE *) 0) {
408 if (!silent) {
409 home();
410 perror(fnam);
411 flags.toplin = 1;
412 pline("Cannot open %s.", fnam);
413 }
414 return (0);
415 }
416 page_more(f, 0);
417 }
418 #endif /* DEF_PAGER */
419
420 return (1);
421 }
422
423 #ifdef UNIX
424 #ifdef SHELL
425 int
dosh(void)426 dosh(void)
427 {
428 char *str;
429 if (child(0)) {
430 if ((str = getenv("SHELL")) != NULL)
431 execl(str, str, (char *)NULL);
432 else
433 execl("/bin/sh", "sh", (char *)NULL);
434 pline("sh: cannot execute.");
435 exit(1);
436 }
437 return (0);
438 }
439 #endif /* SHELL */
440
441 static int
child(int wt)442 child(int wt)
443 {
444 int status;
445 int f;
446
447 f = fork();
448 if (f == 0) { /* child */
449 settty(NULL); /* also calls end_screen() */
450 (void) setuid(getuid());
451 (void) setgid(getgid());
452 #ifdef CHDIR
453 (void) chdir(getenv("HOME"));
454 #endif /* CHDIR */
455 return (1);
456 }
457 if (f == -1) { /* cannot fork */
458 pline("Fork failed. Try again.");
459 return (0);
460 }
461 /* fork succeeded; wait for child to exit */
462 (void) signal(SIGINT, SIG_IGN);
463 (void) signal(SIGQUIT, SIG_IGN);
464 (void) wait(&status);
465 gettty();
466 setftty();
467 (void) signal(SIGINT, done1);
468 #ifdef WIZARD
469 if (wizard)
470 (void) signal(SIGQUIT, SIG_DFL);
471 #endif /* WIZARD */
472 if (wt)
473 getret();
474 docrt();
475 return (0);
476 }
477 #endif /* UNIX */
478