xref: /dragonfly/games/hack/hack.pager.c (revision 0bb9290e) 
1 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
2 /* hack.pager.c - version 1.0.3 */
3 /* $FreeBSD: src/games/hack/hack.pager.c,v 1.7 1999/11/16 02:57:09 billf Exp $ */
4 /* $DragonFly: src/games/hack/hack.pager.c,v 1.4 2006/08/21 19:45:32 pavalos Exp $ */
5 
6 /* This file contains the command routine dowhatis() and a pager. */
7 /* Also readmail() and doshell(), and generally the things that
8    contact the outside world. */
9 
10 #include	<sys/types.h>
11 #include	<sys/signal.h>
12 #include "hack.h"
13 extern int CO, LI;	/* usually COLNO and ROWNO+2 */
14 extern char *CD;
15 extern char quitchars[];
16 
17 static void	intruph(int);
18 static void	page_more(FILE *, int);
19 
20 int
21 dowhatis(void)
22 {
23 	FILE *fp;
24 	char bufr[BUFSZ+6];
25 	char *buf = &bufr[6], *ep, q;
26 
27 	if(!(fp = fopen(DATAFILE, "r")))
28 		pline("Cannot open data file!");
29 	else {
30 		pline("Specify what? ");
31 		q = readchar();
32 		if(q != '\t')
33 		while(fgets(buf,BUFSZ,fp))
34 		    if(*buf == q) {
35 			ep = index(buf, '\n');
36 			if(ep) *ep = 0;
37 			/* else: bad data file */
38 			/* Expand tab 'by hand' */
39 			if(buf[1] == '\t'){
40 				buf = bufr;
41 				buf[0] = q;
42 				strncpy(buf+1, "       ", 7);
43 			}
44 			pline(buf);
45 			if(ep[-1] == ';') {
46 				pline("More info? ");
47 				if(readchar() == 'y') {
48 					page_more(fp,1); /* does fclose() */
49 					return(0);
50 				}
51 			}
52 			fclose(fp); 	/* kopper@psuvax1 */
53 			return(0);
54 		    }
55 		pline("I've never heard of such things.");
56 		fclose(fp);
57 	}
58 	return(0);
59 }
60 
61 /* make the paging of a file interruptible */
62 static int got_intrup;
63 
64 static void
65 intruph(__unused int unused)
66 {
67 	got_intrup++;
68 }
69 
70 /* simple pager, also used from dohelp() */
71 /* strip = nr of chars to be stripped from each line (0 or 1) */
72 static void
73 page_more(FILE *fp, int strip)
74 {
75 	char *bufr, *ep;
76 	sig_t prevsig = signal(SIGINT, intruph);
77 
78 	set_pager(0);
79 	bufr = (char *) alloc((unsigned) CO);
80 	bufr[CO-1] = 0;
81 	while(fgets(bufr,CO-1,fp) && (!strip || *bufr == '\t') && !got_intrup){
82 		ep = index(bufr, '\n');
83 		if(ep)
84 			*ep = 0;
85 		if(page_line(bufr+strip)) {
86 			set_pager(2);
87 			goto ret;
88 		}
89 	}
90 	set_pager(1);
91 ret:
92 	free(bufr);
93 	fclose(fp);
94 	signal(SIGINT, prevsig);
95 	got_intrup = 0;
96 }
97 
98 static boolean whole_screen = TRUE;
99 #define	PAGMIN	12	/* minimum # of lines for page below level map */
100 
101 void
102 set_whole_screen(void)	/* called in termcap as soon as LI is known */
103 {
104 	whole_screen = (LI-ROWNO-2 <= PAGMIN || !CD);
105 }
106 
107 #ifdef NEWS
108 bool
109 readnews(void)
110 {
111 	int ret;
112 
113 	whole_screen = TRUE;	/* force a docrt(), our first */
114 	ret = page_file(NEWS, TRUE);
115 	set_whole_screen();
116 	return(ret);		/* report whether we did docrt() */
117 }
118 #endif /* NEWS */
119 
120 void
121 set_pager(int mode)	/* 0: open  1: wait+close  2: close */
122 {
123 	static boolean so;
124 	if(mode == 0) {
125 		if(!whole_screen) {
126 			/* clear topline */
127 			clrlin();
128 			/* use part of screen below level map */
129 			curs(1, ROWNO+4);
130 		} else {
131 			cls();
132 		}
133 		so = flags.standout;
134 		flags.standout = 1;
135 	} else {
136 		if(mode == 1) {
137 			curs(1, LI);
138 			more();
139 		}
140 		flags.standout = so;
141 		if(whole_screen)
142 			docrt();
143 		else {
144 			curs(1, ROWNO+4);
145 			cl_eos();
146 		}
147 	}
148 }
149 
150 bool
151 page_line(const char *s)	/* returns 1 if we should quit */
152 {
153 	if(cury == LI-1) {
154 		if(!*s)
155 			return(0);	/* suppress blank lines at top */
156 		putchar('\n');
157 		cury++;
158 		cmore("q\033");
159 		if(morc) {
160 			morc = 0;
161 			return(1);
162 		}
163 		if(whole_screen)
164 			cls();
165 		else {
166 			curs(1, ROWNO+4);
167 			cl_eos();
168 		}
169 	}
170 	puts(s);
171 	cury++;
172 	return(0);
173 }
174 
175 /*
176  * Flexible pager: feed it with a number of lines and it will decide
177  * whether these should be fed to the pager above, or displayed in a
178  * corner.
179  * Call:
180  *	cornline(0, title or 0)	: initialize
181  *	cornline(1, text)	: add text to the chain of texts
182  *	cornline(2, morcs)	: output everything and cleanup
183  *	cornline(3, 0)		: cleanup
184  */
185 
186 void
187 cornline(int mode, const char *text)
188 {
189 	static struct line {
190 		struct line *next_line;
191 		char *line_text;
192 	} *texthead, *texttail;
193 	static int maxlen;
194 	static int linect;
195 	struct line *tl;
196 
197 	if(mode == 0) {
198 		texthead = 0;
199 		maxlen = 0;
200 		linect = 0;
201 		if(text) {
202 			cornline(1, text);	/* title */
203 			cornline(1, "");	/* blank line */
204 		}
205 		return;
206 	}
207 
208 	if(mode == 1) {
209 	    int len;
210 
211 	    if(!text) return;	/* superfluous, just to be sure */
212 	    linect++;
213 	    len = strlen(text);
214 	    if(len > maxlen)
215 		maxlen = len;
216 	    tl = (struct line *)
217 		alloc((unsigned)(len + sizeof(struct line) + 1));
218 	    tl->next_line = 0;
219 	    tl->line_text = (char *)(tl + 1);
220 	    strcpy(tl->line_text, text);
221 	    if(!texthead)
222 		texthead = tl;
223 	    else
224 		texttail->next_line = tl;
225 	    texttail = tl;
226 	    return;
227 	}
228 
229 	/* --- now we really do it --- */
230 	if(mode == 2 && linect == 1)			    /* topline only */
231 		pline(texthead->line_text);
232 	else
233 	if(mode == 2) {
234 	    int curline, lth;
235 
236 	    if(flags.toplin == 1) more();	/* ab@unido */
237 	    remember_topl();
238 
239 	    lth = CO - maxlen - 2;		   /* Use full screen width */
240 	    if (linect < LI && lth >= 10) {		     /* in a corner */
241 		home ();
242 		cl_end ();
243 		flags.toplin = 0;
244 		curline = 1;
245 		for (tl = texthead; tl; tl = tl->next_line) {
246 		    curs (lth, curline);
247 		    if(curline > 1)
248 			cl_end ();
249 		    putsym(' ');
250 		    putstr (tl->line_text);
251 		    curline++;
252 		}
253 		curs (lth, curline);
254 		cl_end ();
255 		cmore (text);
256 		home ();
257 		cl_end ();
258 		docorner (lth, curline-1);
259 	    } else {					/* feed to pager */
260 		set_pager(0);
261 		for (tl = texthead; tl; tl = tl->next_line) {
262 		    if (page_line (tl->line_text)) {
263 			set_pager(2);
264 			goto cleanup;
265 		    }
266 		}
267 		if(text) {
268 			cgetret(text);
269 			set_pager(2);
270 		} else
271 			set_pager(1);
272 	    }
273 	}
274 
275 cleanup:
276 	while((tl = texthead)) {
277 		texthead = tl->next_line;
278 		free((char *) tl);
279 	}
280 }
281 
282 int
283 dohelp(void)
284 {
285 	char c;
286 
287 	pline ("Long or short help? ");
288 	while (((c = readchar ()) != 'l') && (c != 's') && !index(quitchars,c))
289 		bell ();
290 	if (!index(quitchars, c))
291 		page_file((c == 'l') ? HELP : SHELP, FALSE);
292 	return(0);
293 }
294 
295 /* return: 0 - cannot open fnam; 1 - otherwise */
296 bool
297 page_file(const char *fnam, bool silent)
298 {
299 #ifdef DEF_PAGER			/* this implies that UNIX is defined */
300       {
301 	/* use external pager; this may give security problems */
302 
303 	int fd = open(fnam, 0);
304 
305 	if(fd < 0) {
306 		if(!silent) pline("Cannot open %s.", fnam);
307 		return(0);
308 	}
309 	if(child(1)){
310 		extern char *catmore;
311 
312 		/* Now that child() does a setuid(getuid()) and a chdir(),
313 		   we may not be able to open file fnam anymore, so make
314 		   it stdin. */
315 		close(0);
316 		if(dup(fd)) {
317 			if(!silent) printf("Cannot open %s as stdin.\n", fnam);
318 		} else {
319 			execl(catmore, "page", (char *) 0);
320 			if(!silent) printf("Cannot exec %s.\n", catmore);
321 		}
322 		exit(1);
323 	}
324 	close(fd);
325       }
326 #else /* DEF_PAGER */
327       {
328 	FILE *f;			/* free after Robert Viduya */
329 
330 	if ((f = fopen (fnam, "r")) == (FILE *) 0) {
331 		if(!silent) {
332 			home(); perror (fnam); flags.toplin = 1;
333 			pline ("Cannot open %s.", fnam);
334 		}
335 		return(0);
336 	}
337 	page_more(f, 0);
338       }
339 #endif /* DEF_PAGER */
340 
341 	return(1);
342 }
343 
344 #ifdef UNIX
345 #ifdef SHELL
346 int
347 dosh(void)
348 {
349 char *str;
350 	if(child(0)) {
351 		if((str = getenv("SHELL")))
352 			execl(str, str, (char *) 0);
353 		else
354 			execl("/bin/sh", "sh", (char *) 0);
355 		pline("sh: cannot execute.");
356 		exit(1);
357 	}
358 	return(0);
359 }
360 #endif /* SHELL */
361 
362 #ifdef NOWAITINCLUDE
363 union wait {		/* used only for the cast  (union wait *) 0  */
364 	int w_status;
365 	struct {
366 		unsigned short w_Termsig:7;
367 		unsigned short w_Coredump:1;
368 		unsigned short w_Retcode:8;
369 	} w_T;
370 };
371 
372 #else
373 
374 #ifdef BSD
375 #include	<sys/wait.h>
376 #else
377 #include	<wait.h>
378 #endif /* BSD */
379 #endif /* NOWAITINCLUDE */
380 
381 bool
382 child(bool wt)
383 {
384 	int status;
385 	int f;
386 
387 	f = fork();
388 	if(f == 0){		/* child */
389 		settty((char *) 0);		/* also calls end_screen() */
390 		/* revoke */
391 		setgid(getgid());
392 #ifdef CHDIR
393 		chdir(getenv("HOME"));
394 #endif /* CHDIR */
395 		return(1);
396 	}
397 	if(f == -1) {	/* cannot fork */
398 		pline("Fork failed. Try again.");
399 		return(0);
400 	}
401 	/* fork succeeded; wait for child to exit */
402 	signal(SIGINT,SIG_IGN);
403 	signal(SIGQUIT,SIG_IGN);
404 	wait(&status);
405 	gettty();
406 	setftty();
407 	signal(SIGINT,done1);
408 #ifdef WIZARD
409 	if(wizard) signal(SIGQUIT,SIG_DFL);
410 #endif /* WIZARD */
411 	if(wt) getret();
412 	docrt();
413 	return(0);
414 }
415 #endif /* UNIX */
416