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hack.pager.c revision 1.12 
      1 /*	$NetBSD: hack.pager.c,v 1.12 2009/06/07 18:30:39 dholland 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 1.12 2009/06/07 18:30:39 dholland 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(void)
     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 					else {
    102 						pline("Bad data file!");
    103 						(void) fclose(fp);
    104 						return(0);
    105 					}
    106 					/* Expand tab 'by hand' */
    107 					if (buf[1] == '\t') {
    108 						buf = bufr;
    109 						buf[0] = q;
    110 						(void) strncpy(buf + 1, "       ", 7);
    111 					}
    112 					pline(buf);
    113 					if (ep[-1] == ';') {
    114 						pline("More info? ");
    115 						if (readchar() == 'y') {
    116 							page_more(fp, 1);	/* does fclose() */
    117 							return (0);
    118 						}
    119 					}
    120 					(void) fclose(fp);	/* kopper@psuvax1 */
    121 					return (0);
    122 				}
    123 		pline("I've never heard of such things.");
    124 		(void) fclose(fp);
    125 	}
    126 	return (0);
    127 }
    128 
    129 /* make the paging of a file interruptible */
    130 static int      got_intrup;
    131 
    132 void
    133 intruph(int n __unused)
    134 {
    135 	got_intrup++;
    136 }
    137 
    138 /* simple pager, also used from dohelp() */
    139 /* strip: nr of chars to be stripped from each line (0 or 1) */
    140 void
    141 page_more(FILE *fp, int strip)
    142 {
    143 	char           *bufr, *ep;
    144 	sig_t           prevsig = signal(SIGINT, intruph);
    145 
    146 	set_pager(0);
    147 	bufr = (char *) alloc((unsigned) CO);
    148 	bufr[CO - 1] = 0;
    149 	while (fgets(bufr, CO - 1, fp) && (!strip || *bufr == '\t') && !got_intrup) {
    150 		ep = strchr(bufr, '\n');
    151 		if (ep)
    152 			*ep = 0;
    153 		if (page_line(bufr + strip)) {
    154 			set_pager(2);
    155 			goto ret;
    156 		}
    157 	}
    158 	set_pager(1);
    159 ret:
    160 	free(bufr);
    161 	(void) fclose(fp);
    162 	(void) signal(SIGINT, prevsig);
    163 	got_intrup = 0;
    164 }
    165 
    166 static boolean  whole_screen = TRUE;
    167 #define	PAGMIN	12		/* minimum # of lines for page below level
    168 				 * map */
    169 
    170 void
    171 set_whole_screen(void)
    172 {				/* called in termcap as soon as LI is known */
    173 	whole_screen = (LI - ROWNO - 2 <= PAGMIN || !CD);
    174 }
    175 
    176 #ifdef NEWS
    177 int
    178 readnews(void)
    179 {
    180 	int             ret;
    181 
    182 	whole_screen = TRUE;	/* force a docrt(), our first */
    183 	ret = page_file(NEWS, TRUE);
    184 	set_whole_screen();
    185 	return (ret);		/* report whether we did docrt() */
    186 }
    187 #endif	/* NEWS */
    188 
    189 /* mode:  0: open  1: wait+close  2: close */
    190 void
    191 set_pager(int mode)
    192 {
    193 	static boolean  so;
    194 	if (mode == 0) {
    195 		if (!whole_screen) {
    196 			/* clear topline */
    197 			clrlin();
    198 			/* use part of screen below level map */
    199 			curs(1, ROWNO + 4);
    200 		} else {
    201 			cls();
    202 		}
    203 		so = flags.standout;
    204 		flags.standout = 1;
    205 	} else {
    206 		if (mode == 1) {
    207 			curs(1, LI);
    208 			more();
    209 		}
    210 		flags.standout = so;
    211 		if (whole_screen)
    212 			docrt();
    213 		else {
    214 			curs(1, ROWNO + 4);
    215 			cl_eos();
    216 		}
    217 	}
    218 }
    219 
    220 int
    221 page_line(const char *s)	/* returns 1 if we should quit */
    222 {
    223 	if (cury == LI - 1) {
    224 		if (!*s)
    225 			return (0);	/* suppress blank lines at top */
    226 		putchar('\n');
    227 		cury++;
    228 		cmore("q\033");
    229 		if (morc) {
    230 			morc = 0;
    231 			return (1);
    232 		}
    233 		if (whole_screen)
    234 			cls();
    235 		else {
    236 			curs(1, ROWNO + 4);
    237 			cl_eos();
    238 		}
    239 	}
    240 	puts(s);
    241 	cury++;
    242 	return (0);
    243 }
    244 
    245 /*
    246  * Flexible pager: feed it with a number of lines and it will decide
    247  * whether these should be fed to the pager above, or displayed in a
    248  * corner.
    249  * Call:
    250  *	cornline(0, title or 0)	: initialize
    251  *	cornline(1, text)	: add text to the chain of texts
    252  *	cornline(2, morcs)	: output everything and cleanup
    253  *	cornline(3, 0)		: cleanup
    254  */
    255 
    256 void
    257 cornline(int mode, const char *text)
    258 {
    259 	static struct line {
    260 		struct line    *next_line;
    261 		char           *line_text;
    262 	}              *texthead, *texttail;
    263 	static int      maxlen;
    264 	static int      linect;
    265 	struct line    *tl;
    266 
    267 	if (mode == 0) {
    268 		texthead = 0;
    269 		maxlen = 0;
    270 		linect = 0;
    271 		if (text) {
    272 			cornline(1, text);	/* title */
    273 			cornline(1, "");	/* blank line */
    274 		}
    275 		return;
    276 	}
    277 	if (mode == 1) {
    278 		int             len;
    279 
    280 		if (!text)
    281 			return;	/* superfluous, just to be sure */
    282 		linect++;
    283 		len = strlen(text);
    284 		if (len > maxlen)
    285 			maxlen = len;
    286 		tl = (struct line *)
    287 			alloc((unsigned) (len + sizeof(struct line) + 1));
    288 		tl->next_line = 0;
    289 		tl->line_text = (char *) (tl + 1);
    290 		(void) strcpy(tl->line_text, text);
    291 		if (!texthead)
    292 			texthead = tl;
    293 		else
    294 			texttail->next_line = tl;
    295 		texttail = tl;
    296 		return;
    297 	}
    298 	/* --- now we really do it --- */
    299 	if (mode == 2 && linect == 1)	/* topline only */
    300 		pline(texthead->line_text);
    301 	else if (mode == 2) {
    302 		int             curline, lth;
    303 
    304 		if (flags.toplin == 1)
    305 			more();	/* ab@unido */
    306 		remember_topl();
    307 
    308 		lth = CO - maxlen - 2;	/* Use full screen width */
    309 		if (linect < LI && lth >= 10) {	/* in a corner */
    310 			home();
    311 			cl_end();
    312 			flags.toplin = 0;
    313 			curline = 1;
    314 			for (tl = texthead; tl; tl = tl->next_line) {
    315 				curs(lth, curline);
    316 				if (curline > 1)
    317 					cl_end();
    318 				putsym(' ');
    319 				putstr(tl->line_text);
    320 				curline++;
    321 			}
    322 			curs(lth, curline);
    323 			cl_end();
    324 			cmore(text);
    325 			home();
    326 			cl_end();
    327 			docorner(lth, curline - 1);
    328 		} else {	/* feed to pager */
    329 			set_pager(0);
    330 			for (tl = texthead; tl; tl = tl->next_line) {
    331 				if (page_line(tl->line_text)) {
    332 					set_pager(2);
    333 					goto cleanup;
    334 				}
    335 			}
    336 			if (text) {
    337 				cgetret(text);
    338 				set_pager(2);
    339 			} else
    340 				set_pager(1);
    341 		}
    342 	}
    343 cleanup:
    344 	while ((tl = texthead) != NULL) {
    345 		texthead = tl->next_line;
    346 		free((char *) tl);
    347 	}
    348 }
    349 
    350 int
    351 dohelp(void)
    352 {
    353 	char            c;
    354 
    355 	pline("Long or short help? ");
    356 	while (((c = readchar()) != 'l') && (c != 's') && !strchr(quitchars, c))
    357 		bell();
    358 	if (!strchr(quitchars, c))
    359 		(void) page_file((c == 'l') ? HELP : SHELP, FALSE);
    360 	return (0);
    361 }
    362 
    363 /* return: 0 - cannot open fnam; 1 - otherwise */
    364 int
    365 page_file(const char *fnam, boolean silent)
    366 {
    367 #ifdef DEF_PAGER		/* this implies that UNIX is defined */
    368 	{
    369 		/* use external pager; this may give security problems */
    370 
    371 		int             fd = open(fnam, O_RDONLY);
    372 
    373 		if (fd < 0) {
    374 			if (!silent)
    375 				pline("Cannot open %s.", fnam);
    376 			return (0);
    377 		}
    378 		if (child(1)) {
    379 
    380 			/*
    381 			 * Now that child() does a setuid(getuid()) and a
    382 			 * chdir(), we may not be able to open file fnam
    383 			 * anymore, so make it stdin.
    384 			 */
    385 			(void) close(0);
    386 			if (dup(fd)) {
    387 				if (!silent)
    388 					printf("Cannot open %s as stdin.\n", fnam);
    389 			} else {
    390 				execl(catmore, "page", (char *) 0);
    391 				if (!silent)
    392 					printf("Cannot exec %s.\n", catmore);
    393 			}
    394 			exit(1);
    395 		}
    396 		(void) close(fd);
    397 	}
    398 #else	/* DEF_PAGER */
    399 	{
    400 		FILE           *f;	/* free after Robert Viduya */
    401 
    402 		if ((f = fopen(fnam, "r")) == (FILE *) 0) {
    403 			if (!silent) {
    404 				home();
    405 				perror(fnam);
    406 				flags.toplin = 1;
    407 				pline("Cannot open %s.", fnam);
    408 			}
    409 			return (0);
    410 		}
    411 		page_more(f, 0);
    412 	}
    413 #endif	/* DEF_PAGER */
    414 
    415 	return (1);
    416 }
    417 
    418 #ifdef UNIX
    419 #ifdef SHELL
    420 int
    421 dosh(void)
    422 {
    423 	char           *str;
    424 	if (child(0)) {
    425 		if ((str = getenv("SHELL")) != NULL)
    426 			execl(str, str, (char *) 0);
    427 		else
    428 			execl("/bin/sh", "sh", (char *) 0);
    429 		pline("sh: cannot execute.");
    430 		exit(1);
    431 	}
    432 	return (0);
    433 }
    434 #endif	/* SHELL */
    435 
    436 #ifdef NOWAITINCLUDE
    437 union wait {			/* used only for the cast  (union wait *) 0  */
    438 	int             w_status;
    439 	struct {
    440 		unsigned short  w_Termsig:7;
    441 		unsigned short  w_Coredump:1;
    442 		unsigned short  w_Retcode:8;
    443 	}               w_T;
    444 };
    445 
    446 #else
    447 
    448 #ifdef BSD
    449 #include	<sys/wait.h>
    450 #else
    451 #include	<wait.h>
    452 #endif	/* BSD */
    453 #endif	/* NOWAITINCLUDE */
    454 
    455 int
    456 child(int wt)
    457 {
    458 	int             status;
    459 	int             f;
    460 
    461 	f = fork();
    462 	if (f == 0) {		/* child */
    463 		settty((char *) 0);	/* also calls end_screen() */
    464 		(void) setuid(getuid());
    465 		(void) setgid(getgid());
    466 #ifdef CHDIR
    467 		(void) chdir(getenv("HOME"));
    468 #endif	/* CHDIR */
    469 		return (1);
    470 	}
    471 	if (f == -1) {		/* cannot fork */
    472 		pline("Fork failed. Try again.");
    473 		return (0);
    474 	}
    475 	/* fork succeeded; wait for child to exit */
    476 	(void) signal(SIGINT, SIG_IGN);
    477 	(void) signal(SIGQUIT, SIG_IGN);
    478 	(void) wait(&status);
    479 	gettty();
    480 	setftty();
    481 	(void) signal(SIGINT, done1);
    482 #ifdef WIZARD
    483 	if (wizard)
    484 		(void) signal(SIGQUIT, SIG_DFL);
    485 #endif	/* WIZARD */
    486 	if (wt)
    487 		getret();
    488 	docrt();
    489 	return (0);
    490 }
    491 #endif	/* UNIX */
    492