Home | History | Annotate | Line # | Download | only in hack
hack.pager.c revision 1.7 
      1 /*	$NetBSD: hack.pager.c,v 1.7 2003/04/02 18:36:39 jsm 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 (at) 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 1.7 2003/04/02 18:36:39 jsm 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 <signal.h>
     77 #include <stdlib.h>
     78 #include <unistd.h>
     79 #include "hack.h"
     80 #include "extern.h"
     81 
     82 int
     83 dowhatis()
     84 {
     85 	FILE           *fp;
     86 	char            bufr[BUFSZ + 6];
     87 	char           *buf = &bufr[6], *ep, q;
     88 
     89 	if (!(fp = fopen(DATAFILE, "r")))
     90 		pline("Cannot open data file!");
     91 	else {
     92 		pline("Specify what? ");
     93 		q = readchar();
     94 		if (q != '\t')
     95 			while (fgets(buf, BUFSZ, fp))
     96 				if (*buf == q) {
     97 					ep = strchr(buf, '\n');
     98 					if (ep)
     99 						*ep = 0;
    100 					/* else: bad data file */
    101 					/* Expand tab 'by hand' */
    102 					if (buf[1] == '\t') {
    103 						buf = bufr;
    104 						buf[0] = q;
    105 						(void) strncpy(buf + 1, "       ", 7);
    106 					}
    107 					pline(buf);
    108 					if (ep[-1] == ';') {
    109 						pline("More info? ");
    110 						if (readchar() == 'y') {
    111 							page_more(fp, 1);	/* does fclose() */
    112 							return (0);
    113 						}
    114 					}
    115 					(void) fclose(fp);	/* kopper@psuvax1 */
    116 					return (0);
    117 				}
    118 		pline("I've never heard of such things.");
    119 		(void) fclose(fp);
    120 	}
    121 	return (0);
    122 }
    123 
    124 /* make the paging of a file interruptible */
    125 static int      got_intrup;
    126 
    127 void
    128 intruph(n)
    129 	int n __attribute__((__unused__));
    130 {
    131 	got_intrup++;
    132 }
    133 
    134 /* simple pager, also used from dohelp() */
    135 void
    136 page_more(fp, strip)
    137 	FILE           *fp;
    138 	int             strip;	/* nr of chars to be stripped from each line
    139 				 * (0 or 1) */
    140 {
    141 	char           *bufr, *ep;
    142 	sig_t           prevsig = signal(SIGINT, intruph);
    143 
    144 	set_pager(0);
    145 	bufr = (char *) alloc((unsigned) CO);
    146 	bufr[CO - 1] = 0;
    147 	while (fgets(bufr, CO - 1, fp) && (!strip || *bufr == '\t') && !got_intrup) {
    148 		ep = strchr(bufr, '\n');
    149 		if (ep)
    150 			*ep = 0;
    151 		if (page_line(bufr + strip)) {
    152 			set_pager(2);
    153 			goto ret;
    154 		}
    155 	}
    156 	set_pager(1);
    157 ret:
    158 	free(bufr);
    159 	(void) fclose(fp);
    160 	(void) signal(SIGINT, prevsig);
    161 	got_intrup = 0;
    162 }
    163 
    164 static boolean  whole_screen = TRUE;
    165 #define	PAGMIN	12		/* minimum # of lines for page below level
    166 				 * map */
    167 
    168 void
    169 set_whole_screen()
    170 {				/* called in termcap as soon as LI is known */
    171 	whole_screen = (LI - ROWNO - 2 <= PAGMIN || !CD);
    172 }
    173 
    174 #ifdef NEWS
    175 int
    176 readnews()
    177 {
    178 	int             ret;
    179 
    180 	whole_screen = TRUE;	/* force a docrt(), our first */
    181 	ret = page_file(NEWS, TRUE);
    182 	set_whole_screen();
    183 	return (ret);		/* report whether we did docrt() */
    184 }
    185 #endif	/* NEWS */
    186 
    187 void
    188 set_pager(mode)
    189 	int             mode;	/* 0: open  1: wait+close  2: close */
    190 {
    191 	static boolean  so;
    192 	if (mode == 0) {
    193 		if (!whole_screen) {
    194 			/* clear topline */
    195 			clrlin();
    196 			/* use part of screen below level map */
    197 			curs(1, ROWNO + 4);
    198 		} else {
    199 			cls();
    200 		}
    201 		so = flags.standout;
    202 		flags.standout = 1;
    203 	} else {
    204 		if (mode == 1) {
    205 			curs(1, LI);
    206 			more();
    207 		}
    208 		flags.standout = so;
    209 		if (whole_screen)
    210 			docrt();
    211 		else {
    212 			curs(1, ROWNO + 4);
    213 			cl_eos();
    214 		}
    215 	}
    216 }
    217 
    218 int
    219 page_line(s)			/* returns 1 if we should quit */
    220 	const char           *s;
    221 {
    222 	if (cury == LI - 1) {
    223 		if (!*s)
    224 			return (0);	/* suppress blank lines at top */
    225 		putchar('\n');
    226 		cury++;
    227 		cmore("q\033");
    228 		if (morc) {
    229 			morc = 0;
    230 			return (1);
    231 		}
    232 		if (whole_screen)
    233 			cls();
    234 		else {
    235 			curs(1, ROWNO + 4);
    236 			cl_eos();
    237 		}
    238 	}
    239 	puts(s);
    240 	cury++;
    241 	return (0);
    242 }
    243 
    244 /*
    245  * Flexible pager: feed it with a number of lines and it will decide
    246  * whether these should be fed to the pager above, or displayed in a
    247  * corner.
    248  * Call:
    249  *	cornline(0, title or 0)	: initialize
    250  *	cornline(1, text)	: add text to the chain of texts
    251  *	cornline(2, morcs)	: output everything and cleanup
    252  *	cornline(3, 0)		: cleanup
    253  */
    254 
    255 void
    256 cornline(mode, text)
    257 	int             mode;
    258 	const char           *text;
    259 {
    260 	static struct line {
    261 		struct line    *next_line;
    262 		char           *line_text;
    263 	}              *texthead, *texttail;
    264 	static int      maxlen;
    265 	static int      linect;
    266 	struct line    *tl;
    267 
    268 	if (mode == 0) {
    269 		texthead = 0;
    270 		maxlen = 0;
    271 		linect = 0;
    272 		if (text) {
    273 			cornline(1, text);	/* title */
    274 			cornline(1, "");	/* blank line */
    275 		}
    276 		return;
    277 	}
    278 	if (mode == 1) {
    279 		int             len;
    280 
    281 		if (!text)
    282 			return;	/* superfluous, just to be sure */
    283 		linect++;
    284 		len = strlen(text);
    285 		if (len > maxlen)
    286 			maxlen = len;
    287 		tl = (struct line *)
    288 			alloc((unsigned) (len + sizeof(struct line) + 1));
    289 		tl->next_line = 0;
    290 		tl->line_text = (char *) (tl + 1);
    291 		(void) strcpy(tl->line_text, text);
    292 		if (!texthead)
    293 			texthead = tl;
    294 		else
    295 			texttail->next_line = tl;
    296 		texttail = tl;
    297 		return;
    298 	}
    299 	/* --- now we really do it --- */
    300 	if (mode == 2 && linect == 1)	/* topline only */
    301 		pline(texthead->line_text);
    302 	else if (mode == 2) {
    303 		int             curline, lth;
    304 
    305 		if (flags.toplin == 1)
    306 			more();	/* ab@unido */
    307 		remember_topl();
    308 
    309 		lth = CO - maxlen - 2;	/* Use full screen width */
    310 		if (linect < LI && lth >= 10) {	/* in a corner */
    311 			home();
    312 			cl_end();
    313 			flags.toplin = 0;
    314 			curline = 1;
    315 			for (tl = texthead; tl; tl = tl->next_line) {
    316 				curs(lth, curline);
    317 				if (curline > 1)
    318 					cl_end();
    319 				putsym(' ');
    320 				putstr(tl->line_text);
    321 				curline++;
    322 			}
    323 			curs(lth, curline);
    324 			cl_end();
    325 			cmore(text);
    326 			home();
    327 			cl_end();
    328 			docorner(lth, curline - 1);
    329 		} else {	/* feed to pager */
    330 			set_pager(0);
    331 			for (tl = texthead; tl; tl = tl->next_line) {
    332 				if (page_line(tl->line_text)) {
    333 					set_pager(2);
    334 					goto cleanup;
    335 				}
    336 			}
    337 			if (text) {
    338 				cgetret(text);
    339 				set_pager(2);
    340 			} else
    341 				set_pager(1);
    342 		}
    343 	}
    344 cleanup:
    345 	while ((tl = texthead) != NULL) {
    346 		texthead = tl->next_line;
    347 		free((char *) tl);
    348 	}
    349 }
    350 
    351 int
    352 dohelp()
    353 {
    354 	char            c;
    355 
    356 	pline("Long or short help? ");
    357 	while (((c = readchar()) != 'l') && (c != 's') && !strchr(quitchars, c))
    358 		bell();
    359 	if (!strchr(quitchars, c))
    360 		(void) page_file((c == 'l') ? HELP : SHELP, FALSE);
    361 	return (0);
    362 }
    363 
    364 int
    365 page_file(fnam, silent)		/* return: 0 - cannot open fnam; 1 -
    366 				 * otherwise */
    367 	const char           *fnam;
    368 	boolean         silent;
    369 {
    370 #ifdef DEF_PAGER		/* this implies that UNIX is defined */
    371 	{
    372 		/* use external pager; this may give security problems */
    373 
    374 		int             fd = open(fnam, O_RDONLY);
    375 
    376 		if (fd < 0) {
    377 			if (!silent)
    378 				pline("Cannot open %s.", fnam);
    379 			return (0);
    380 		}
    381 		if (child(1)) {
    382 
    383 			/*
    384 			 * Now that child() does a setuid(getuid()) and a
    385 			 * chdir(), we may not be able to open file fnam
    386 			 * anymore, so make it stdin.
    387 			 */
    388 			(void) close(0);
    389 			if (dup(fd)) {
    390 				if (!silent)
    391 					printf("Cannot open %s as stdin.\n", fnam);
    392 			} else {
    393 				execl(catmore, "page", (char *) 0);
    394 				if (!silent)
    395 					printf("Cannot exec %s.\n", catmore);
    396 			}
    397 			exit(1);
    398 		}
    399 		(void) close(fd);
    400 	}
    401 #else	/* DEF_PAGER */
    402 	{
    403 		FILE           *f;	/* free after Robert Viduya */
    404 
    405 		if ((f = fopen(fnam, "r")) == (FILE *) 0) {
    406 			if (!silent) {
    407 				home();
    408 				perror(fnam);
    409 				flags.toplin = 1;
    410 				pline("Cannot open %s.", fnam);
    411 			}
    412 			return (0);
    413 		}
    414 		page_more(f, 0);
    415 	}
    416 #endif	/* DEF_PAGER */
    417 
    418 	return (1);
    419 }
    420 
    421 #ifdef UNIX
    422 #ifdef SHELL
    423 int
    424 dosh()
    425 {
    426 	char           *str;
    427 	if (child(0)) {
    428 		if ((str = getenv("SHELL")) != NULL)
    429 			execl(str, str, (char *) 0);
    430 		else
    431 			execl("/bin/sh", "sh", (char *) 0);
    432 		pline("sh: cannot execute.");
    433 		exit(1);
    434 	}
    435 	return (0);
    436 }
    437 #endif	/* SHELL */
    438 
    439 #ifdef NOWAITINCLUDE
    440 union wait {			/* used only for the cast  (union wait *) 0  */
    441 	int             w_status;
    442 	struct {
    443 		unsigned short  w_Termsig:7;
    444 		unsigned short  w_Coredump:1;
    445 		unsigned short  w_Retcode:8;
    446 	}               w_T;
    447 };
    448 
    449 #else
    450 
    451 #ifdef BSD
    452 #include	<sys/wait.h>
    453 #else
    454 #include	<wait.h>
    455 #endif	/* BSD */
    456 #endif	/* NOWAITINCLUDE */
    457 
    458 int
    459 child(int wt)
    460 {
    461 	int             status;
    462 	int             f;
    463 
    464 	f = fork();
    465 	if (f == 0) {		/* child */
    466 		settty((char *) 0);	/* also calls end_screen() */
    467 		(void) setuid(getuid());
    468 		(void) setgid(getgid());
    469 #ifdef CHDIR
    470 		(void) chdir(getenv("HOME"));
    471 #endif	/* CHDIR */
    472 		return (1);
    473 	}
    474 	if (f == -1) {		/* cannot fork */
    475 		pline("Fork failed. Try again.");
    476 		return (0);
    477 	}
    478 	/* fork succeeded; wait for child to exit */
    479 	(void) signal(SIGINT, SIG_IGN);
    480 	(void) signal(SIGQUIT, SIG_IGN);
    481 	(void) wait(&status);
    482 	gettty();
    483 	setftty();
    484 	(void) signal(SIGINT, done1);
    485 #ifdef WIZARD
    486 	if (wizard)
    487 		(void) signal(SIGQUIT, SIG_DFL);
    488 #endif	/* WIZARD */
    489 	if (wt)
    490 		getret();
    491 	docrt();
    492 	return (0);
    493 }
    494 #endif	/* UNIX */
    495