msgs.c revision 49061 
1/*-
2 * Copyright (c) 1980, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#ifndef lint
35static const char copyright[] =
36"@(#) Copyright (c) 1980, 1993\n\
37	The Regents of the University of California.  All rights reserved.\n";
38#endif /* not lint */
39
40#ifndef lint
41#if 0
42static char sccsid[] = "@(#)msgs.c	8.2 (Berkeley) 4/28/95";
43#endif
44static const char rcsid[] =
45	"$Id: msgs.c,v 1.13 1998/07/14 19:07:30 ghelmer Exp $";
46#endif /* not lint */
47
48/*
49 * msgs - a user bulletin board program
50 *
51 * usage:
52 *	msgs [fhlopq] [[-]number]	to read messages
53 *	msgs -s				to place messages
54 *	msgs -c [-days]			to clean up the bulletin board
55 *
56 * prompt commands are:
57 *	y	print message
58 *	n	flush message, go to next message
59 *	q	flush message, quit
60 *	p	print message, turn on 'pipe thru more' mode
61 *	P	print message, turn off 'pipe thru more' mode
62 *	-	reprint last message
63 *	s[-][<num>] [<filename>]	save message
64 *	m[-][<num>]	mail with message in temp mbox
65 *	x	exit without flushing this message
66 *	<num>	print message number <num>
67 */
68
69#define V7		/* will look for TERM in the environment */
70#define OBJECT		/* will object to messages without Subjects */
71/* #define REJECT */	/* will reject messages without Subjects
72			   (OBJECT must be defined also) */
73/* #define UNBUFFERED *//* use unbuffered output */
74
75#include <sys/param.h>
76#include <sys/stat.h>
77#include <ctype.h>
78#include <dirent.h>
79#include <err.h>
80#include <errno.h>
81#include <fcntl.h>
82#include <locale.h>
83#include <pwd.h>
84#include <setjmp.h>
85#include <termcap.h>
86#include <termios.h>
87#include <signal.h>
88#include <stdio.h>
89#include <stdlib.h>
90#include <string.h>
91#include <time.h>
92#include <unistd.h>
93#include "pathnames.h"
94
95#define	CMODE	0644		/* bounds file creation	mode */
96#define NO	0
97#define YES	1
98#define SUPERUSER	0	/* superuser uid */
99#define DAEMON		1	/* daemon uid */
100#define NLINES	24		/* default number of lines/crt screen */
101#define NDAYS	21		/* default keep time for messages */
102#define DAYS	*24*60*60	/* seconds/day */
103#define MSGSRC	".msgsrc"	/* user's rc file */
104#define BOUNDS	"bounds"	/* message bounds file */
105#define NEXT	"Next message? [yq]"
106#define MORE	"More? [ynq]"
107#define NOMORE	"(No more) [q] ?"
108
109typedef	char	bool;
110
111FILE	*msgsrc;
112FILE	*newmsg;
113char	*sep = "-";
114char	inbuf[BUFSIZ];
115char	fname[MAXPATHLEN];
116char	cmdbuf[MAXPATHLEN + MAXPATHLEN];
117char	subj[128];
118char	from[128];
119char	date[128];
120char	*ptr;
121char	*in;
122bool	local;
123bool	ruptible;
124bool	totty;
125bool	seenfrom;
126bool	seensubj;
127bool	blankline;
128bool	printing = NO;
129bool	mailing = NO;
130bool	quitit = NO;
131bool	sending = NO;
132bool	intrpflg = NO;
133int	uid;
134int	msg;
135int	prevmsg;
136int	lct;
137int	nlines;
138int	Lpp = 0;
139time_t	t;
140time_t	keep;
141
142/* option initialization */
143bool	hdrs = NO;
144bool	qopt = NO;
145bool	hush = NO;
146bool	send_msg = NO;
147bool	locomode = NO;
148bool	use_pager = NO;
149bool	clean = NO;
150bool	lastcmd = NO;
151jmp_buf	tstpbuf;
152
153
154void ask __P((char *));
155void gfrsub __P((FILE *));
156int linecnt __P((FILE *));
157int next __P((char *));
158char *nxtfld __P((unsigned char *));
159void onsusp __P((int));
160void onintr __P((int));
161void prmesg __P((int));
162static void usage __P((void));
163
164int
165main(argc, argv)
166int argc; char *argv[];
167{
168	bool newrc, already;
169	int rcfirst = 0;		/* first message to print (from .rc) */
170	int rcback = 0;			/* amount to back off of rcfirst */
171	int firstmsg = 0, nextmsg = 0, lastmsg = 0;
172	int blast = 0;
173	struct stat buf;		/* stat to check access of bounds */
174	FILE *bounds;
175
176#ifdef UNBUFFERED
177	setbuf(stdout, NULL);
178#endif
179	setlocale(LC_ALL, "");
180
181	time(&t);
182	setuid(uid = getuid());
183	ruptible = (signal(SIGINT, SIG_IGN) == SIG_DFL);
184	if (ruptible)
185		signal(SIGINT, SIG_DFL);
186
187	argc--, argv++;
188	while (argc > 0) {
189		if (isdigit(argv[0][0])) {	/* starting message # */
190			rcfirst = atoi(argv[0]);
191		}
192		else if (isdigit(argv[0][1])) {	/* backward offset */
193			rcback = atoi( &( argv[0][1] ) );
194		}
195		else {
196			ptr = *argv;
197			while (*ptr) switch (*ptr++) {
198
199			case '-':
200				break;
201
202			case 'c':
203				if (uid != SUPERUSER && uid != DAEMON) {
204					fprintf(stderr, "Sorry\n");
205					exit(1);
206				}
207				clean = YES;
208				break;
209
210			case 'f':		/* silently */
211				hush = YES;
212				break;
213
214			case 'h':		/* headers only */
215				hdrs = YES;
216				break;
217
218			case 'l':		/* local msgs only */
219				locomode = YES;
220				break;
221
222			case 'o':		/* option to save last message */
223				lastcmd = YES;
224				break;
225
226			case 'p':		/* pipe thru 'more' during long msgs */
227				use_pager = YES;
228				break;
229
230			case 'q':		/* query only */
231				qopt = YES;
232				break;
233
234			case 's':		/* sending TO msgs */
235				send_msg = YES;
236				break;
237
238			default:
239				usage();
240			}
241		}
242		argc--, argv++;
243	}
244
245	/*
246	 * determine current message bounds
247	 */
248	snprintf(fname, sizeof(fname), "%s/%s", _PATH_MSGS, BOUNDS);
249
250	/*
251	 * Test access rights to the bounds file
252	 * This can be a little tricky.  if(send_msg), then
253	 * we will create it.  We assume that if(send_msg),
254	 * then you have write permission there.
255	 * Else, it better be there, or we bail.
256	 */
257	if (send_msg != YES) {
258		if (stat(fname, &buf) < 0) {
259			if (hush != YES) {
260				err(errno, "%s", fname);
261			} else {
262				exit(1);
263			}
264		}
265	}
266	bounds = fopen(fname, "r");
267
268	if (bounds != NULL) {
269		fscanf(bounds, "%d %d\n", &firstmsg, &lastmsg);
270		fclose(bounds);
271		blast = lastmsg;	/* save upper bound */
272	}
273
274	if (clean)
275		keep = t - (rcback? rcback : NDAYS) DAYS;
276
277	if (clean || bounds == NULL) {	/* relocate message bounds */
278		struct dirent *dp;
279		struct stat stbuf;
280		bool seenany = NO;
281		DIR	*dirp;
282
283		dirp = opendir(_PATH_MSGS);
284		if (dirp == NULL)
285			err(errno, "%s", _PATH_MSGS);
286
287		firstmsg = 32767;
288		lastmsg = 0;
289
290		for (dp = readdir(dirp); dp != NULL; dp = readdir(dirp)){
291			register char *cp = dp->d_name;
292			register int i = 0;
293
294			if (dp->d_ino == 0)
295				continue;
296			if (dp->d_namlen == 0)
297				continue;
298
299			if (clean)
300				snprintf(inbuf, sizeof(inbuf), "%s/%s", _PATH_MSGS, cp);
301
302			while (isdigit(*cp))
303				i = i * 10 + *cp++ - '0';
304			if (*cp)
305				continue;	/* not a message! */
306
307			if (clean) {
308				if (stat(inbuf, &stbuf) != 0)
309					continue;
310				if (stbuf.st_mtime < keep
311				    && stbuf.st_mode&S_IWRITE) {
312					unlink(inbuf);
313					continue;
314				}
315			}
316
317			if (i > lastmsg)
318				lastmsg = i;
319			if (i < firstmsg)
320				firstmsg = i;
321			seenany = YES;
322		}
323		closedir(dirp);
324
325		if (!seenany) {
326			if (blast != 0)	/* never lower the upper bound! */
327				lastmsg = blast;
328			firstmsg = lastmsg + 1;
329		}
330		else if (blast > lastmsg)
331			lastmsg = blast;
332
333		if (!send_msg) {
334			bounds = fopen(fname, "w");
335			if (bounds == NULL)
336				err(errno, "%s", fname);
337			chmod(fname, CMODE);
338			fprintf(bounds, "%d %d\n", firstmsg, lastmsg);
339			fclose(bounds);
340		}
341	}
342
343	if (send_msg) {
344		/*
345		 * Send mode - place msgs in _PATH_MSGS
346		 */
347		bounds = fopen(fname, "w");
348		if (bounds == NULL)
349			err(errno, "%s", fname);
350
351		nextmsg = lastmsg + 1;
352		snprintf(fname, sizeof(fname), "%s/%d", _PATH_MSGS, nextmsg);
353		newmsg = fopen(fname, "w");
354		if (newmsg == NULL)
355			err(errno, "%s", fname);
356		chmod(fname, CMODE);
357
358		fprintf(bounds, "%d %d\n", firstmsg, nextmsg);
359		fclose(bounds);
360
361		sending = YES;
362		if (ruptible)
363			signal(SIGINT, onintr);
364
365		if (isatty(fileno(stdin))) {
366			ptr = getpwuid(uid)->pw_name;
367			printf("Message %d:\nFrom %s %sSubject: ",
368				nextmsg, ptr, ctime(&t));
369			fflush(stdout);
370			fgets(inbuf, sizeof inbuf, stdin);
371			putchar('\n');
372			fflush(stdout);
373			fprintf(newmsg, "From %s %sSubject: %s\n",
374				ptr, ctime(&t), inbuf);
375			blankline = seensubj = YES;
376		}
377		else
378			blankline = seensubj = NO;
379		for (;;) {
380			fgets(inbuf, sizeof inbuf, stdin);
381			if (feof(stdin) || ferror(stdin))
382				break;
383			blankline = (blankline || (inbuf[0] == '\n'));
384			seensubj = (seensubj || (!blankline && (strncmp(inbuf, "Subj", 4) == 0)));
385			fputs(inbuf, newmsg);
386		}
387#ifdef OBJECT
388		if (!seensubj) {
389			printf("NOTICE: Messages should have a Subject field!\n");
390#ifdef REJECT
391			unlink(fname);
392#endif
393			exit(1);
394		}
395#endif
396		exit(ferror(stdin));
397	}
398	if (clean)
399		exit(0);
400
401	/*
402	 * prepare to display messages
403	 */
404	totty = (isatty(fileno(stdout)) != 0);
405	use_pager = use_pager && totty;
406
407	snprintf(fname, sizeof(fname), "%s/%s", getenv("HOME"), MSGSRC);
408	msgsrc = fopen(fname, "r");
409	if (msgsrc) {
410		newrc = NO;
411		fscanf(msgsrc, "%d\n", &nextmsg);
412		fclose(msgsrc);
413		if (nextmsg > lastmsg+1) {
414			printf("Warning: bounds have been reset (%d, %d)\n",
415				firstmsg, lastmsg);
416			truncate(fname, (off_t)0);
417			newrc = YES;
418		}
419		else if (!rcfirst)
420			rcfirst = nextmsg - rcback;
421	}
422	else
423		newrc = YES;
424	msgsrc = fopen(fname, "r+");
425	if (msgsrc == NULL)
426		msgsrc = fopen(fname, "w");
427	if (msgsrc == NULL)
428		err(errno, "%s", fname);
429	if (rcfirst) {
430		if (rcfirst > lastmsg+1) {
431			printf("Warning: the last message is number %d.\n",
432				lastmsg);
433			rcfirst = nextmsg;
434		}
435		if (rcfirst > firstmsg)
436			firstmsg = rcfirst;	/* don't set below first msg */
437	}
438	if (newrc) {
439		nextmsg = firstmsg;
440		fseek(msgsrc, 0L, 0);
441		fprintf(msgsrc, "%d\n", nextmsg);
442		fflush(msgsrc);
443	}
444
445#ifdef V7
446	if (totty) {
447		struct winsize win;
448		if (ioctl(fileno(stdout), TIOCGWINSZ, &win) != -1)
449			Lpp = win.ws_row;
450		if (Lpp <= 0) {
451			if (tgetent(inbuf, getenv("TERM")) <= 0
452			    || (Lpp = tgetnum("li")) <= 0) {
453				Lpp = NLINES;
454			}
455		}
456	}
457#endif
458	Lpp -= 6;	/* for headers, etc. */
459
460	already = NO;
461	prevmsg = firstmsg;
462	printing = YES;
463	if (ruptible)
464		signal(SIGINT, onintr);
465
466	/*
467	 * Main program loop
468	 */
469	for (msg = firstmsg; msg <= lastmsg; msg++) {
470
471		snprintf(fname, sizeof(fname), "%s/%d", _PATH_MSGS, msg);
472		newmsg = fopen(fname, "r");
473		if (newmsg == NULL)
474			continue;
475
476		gfrsub(newmsg);		/* get From and Subject fields */
477		if (locomode && !local) {
478			fclose(newmsg);
479			continue;
480		}
481
482		if (qopt) {	/* This has to be located here */
483			printf("There are new messages.\n");
484			exit(0);
485		}
486
487		if (already && !hdrs)
488			putchar('\n');
489
490		/*
491		 * Print header
492		 */
493		if (totty)
494			signal(SIGTSTP, onsusp);
495		(void) setjmp(tstpbuf);
496		already = YES;
497		nlines = 2;
498		if (seenfrom) {
499			printf("Message %d:\nFrom %s %s", msg, from, date);
500			nlines++;
501		}
502		if (seensubj) {
503			printf("Subject: %s", subj);
504			nlines++;
505		}
506		else {
507			if (seenfrom) {
508				putchar('\n');
509				nlines++;
510			}
511			while (nlines < 6
512			    && fgets(inbuf, sizeof inbuf, newmsg)
513			    && inbuf[0] != '\n') {
514				fputs(inbuf, stdout);
515				nlines++;
516			}
517		}
518
519		lct = linecnt(newmsg);
520		if (lct)
521			printf("(%d%slines) ", lct, seensubj? " " : " more ");
522
523		if (hdrs) {
524			printf("\n-----\n");
525			fclose(newmsg);
526			continue;
527		}
528
529		/*
530		 * Ask user for command
531		 */
532		if (totty)
533			ask(lct? MORE : (msg==lastmsg? NOMORE : NEXT));
534		else
535			inbuf[0] = 'y';
536		if (totty)
537			signal(SIGTSTP, SIG_DFL);
538cmnd:
539		in = inbuf;
540		switch (*in) {
541			case 'x':
542			case 'X':
543				exit(0);
544
545			case 'q':
546			case 'Q':
547				quitit = YES;
548				printf("--Postponed--\n");
549				exit(0);
550				/* intentional fall-thru */
551			case 'n':
552			case 'N':
553				if (msg >= nextmsg) sep = "Flushed";
554				prevmsg = msg;
555				break;
556
557			case 'p':
558			case 'P':
559				use_pager = (*in++ == 'p');
560				/* intentional fallthru */
561			case '\n':
562			case 'y':
563			default:
564				if (*in == '-') {
565					msg = prevmsg-1;
566					sep = "replay";
567					break;
568				}
569				if (isdigit(*in)) {
570					msg = next(in);
571					sep = in;
572					break;
573				}
574
575				prmesg(nlines + lct + (seensubj? 1 : 0));
576				prevmsg = msg;
577
578		}
579
580		printf("--%s--\n", sep);
581		sep = "-";
582		if (msg >= nextmsg) {
583			nextmsg = msg + 1;
584			fseek(msgsrc, 0L, 0);
585			fprintf(msgsrc, "%d\n", nextmsg);
586			fflush(msgsrc);
587		}
588		if (newmsg)
589			fclose(newmsg);
590		if (quitit)
591			break;
592	}
593
594	/*
595	 * Make sure .rc file gets updated
596	 */
597	if (--msg >= nextmsg) {
598		nextmsg = msg + 1;
599		fseek(msgsrc, 0L, 0);
600		fprintf(msgsrc, "%d\n", nextmsg);
601		fflush(msgsrc);
602	}
603	if (already && !quitit && lastcmd && totty) {
604		/*
605		 * save or reply to last message?
606		 */
607		msg = prevmsg;
608		ask(NOMORE);
609		if (inbuf[0] == '-' || isdigit(inbuf[0]))
610			goto cmnd;
611	}
612	if (!(already || hush || qopt))
613		printf("No new messages.\n");
614	exit(0);
615}
616
617static void
618usage()
619{
620	fprintf(stderr, "usage: msgs [fhlopq] [[-]number]\n");
621	exit(1);
622}
623
624void
625prmesg(length)
626int length;
627{
628	FILE *outf;
629	char *env_pager;
630
631	if (use_pager && length > Lpp) {
632		signal(SIGPIPE, SIG_IGN);
633		signal(SIGQUIT, SIG_IGN);
634		if ((env_pager = getenv("PAGER")) == NULL) {
635			snprintf(cmdbuf, sizeof(cmdbuf), _PATH_PAGER, Lpp);
636		} else {
637			snprintf(cmdbuf, sizeof(cmdbuf), env_pager);
638		}
639		outf = popen(cmdbuf, "w");
640		if (!outf)
641			outf = stdout;
642		else
643			setbuf(outf, (char *)NULL);
644	}
645	else
646		outf = stdout;
647
648	if (seensubj)
649		putc('\n', outf);
650
651	while (fgets(inbuf, sizeof inbuf, newmsg)) {
652		fputs(inbuf, outf);
653		if (ferror(outf)) {
654			clearerr(outf);
655			break;
656		}
657	}
658
659	if (outf != stdout) {
660		pclose(outf);
661		signal(SIGPIPE, SIG_DFL);
662		signal(SIGQUIT, SIG_DFL);
663	}
664	else {
665		fflush(stdout);
666	}
667
668	/* force wait on output */
669	tcdrain(fileno(stdout));
670}
671
672void
673onintr(unused)
674	int unused;
675{
676	signal(SIGINT, onintr);
677	if (mailing)
678		unlink(fname);
679	if (sending) {
680		unlink(fname);
681		puts("--Killed--");
682		exit(1);
683	}
684	if (printing) {
685		putchar('\n');
686		if (hdrs)
687			exit(0);
688		sep = "Interrupt";
689		if (newmsg)
690			fseek(newmsg, 0L, 2);
691		intrpflg = YES;
692	}
693}
694
695/*
696 * We have just gotten a susp.  Suspend and prepare to resume.
697 */
698void
699onsusp(unused)
700	int unused;
701{
702	signal(SIGTSTP, SIG_DFL);
703	sigsetmask(0);
704	kill(0, SIGTSTP);
705	signal(SIGTSTP, onsusp);
706	if (!mailing)
707		longjmp(tstpbuf, 0);
708}
709
710int
711linecnt(f)
712FILE *f;
713{
714	off_t oldpos = ftell(f);
715	int l = 0;
716	char lbuf[BUFSIZ];
717
718	while (fgets(lbuf, sizeof lbuf, f))
719		l++;
720	clearerr(f);
721	fseek(f, oldpos, 0);
722	return (l);
723}
724
725int
726next(buf)
727char *buf;
728{
729	int i;
730	sscanf(buf, "%d", &i);
731	sprintf(buf, "Goto %d", i);
732	return(--i);
733}
734
735void
736ask(prompt)
737char *prompt;
738{
739	char	inch;
740	int	n, cmsg, fd;
741	off_t	oldpos;
742	FILE	*cpfrom, *cpto;
743
744	printf("%s ", prompt);
745	fflush(stdout);
746	intrpflg = NO;
747	(void) fgets(inbuf, sizeof inbuf, stdin);
748	if ((n = strlen(inbuf)) > 0 && inbuf[n - 1] == '\n')
749		inbuf[n - 1] = '\0';
750	if (intrpflg)
751		inbuf[0] = 'x';
752
753	/*
754	 * Handle 'mail' and 'save' here.
755	 */
756	if ((inch = inbuf[0]) == 's' || inch == 'm') {
757		if (inbuf[1] == '-')
758			cmsg = prevmsg;
759		else if (isdigit(inbuf[1]))
760			cmsg = atoi(&inbuf[1]);
761		else
762			cmsg = msg;
763		snprintf(fname, sizeof(fname), "%s/%d", _PATH_MSGS, cmsg);
764
765		oldpos = ftell(newmsg);
766
767		cpfrom = fopen(fname, "r");
768		if (!cpfrom) {
769			printf("Message %d not found\n", cmsg);
770			ask (prompt);
771			return;
772		}
773
774		if (inch == 's') {
775			in = nxtfld(inbuf);
776			if (*in) {
777				for (n=0; in[n] > ' '; n++) { /* sizeof fname? */
778					fname[n] = in[n];
779				}
780				fname[n] = NULL;
781			}
782			else
783				strcpy(fname, "Messages");
784			fd = open(fname, O_RDWR|O_EXCL|O_CREAT|O_APPEND);
785		}
786		else {
787			strcpy(fname, _PATH_TMP);
788			fd = mkstemp(fname);
789			if (fd != -1) {
790				snprintf(cmdbuf, sizeof(cmdbuf), _PATH_MAIL,
791				    fname);
792				mailing = YES;
793			}
794		}
795		if (fd == -1 || (cpto = fdopen(fd, "a")) == NULL) {
796			if (fd != -1)
797				close(fd);
798			warn("%s", fname);
799			mailing = NO;
800			fseek(newmsg, oldpos, 0);
801			ask(prompt);
802			return;
803		}
804
805		while ((n = fread(inbuf, 1, sizeof inbuf, cpfrom)))
806			fwrite(inbuf, 1, n, cpto);
807
808		fclose(cpfrom);
809		fclose(cpto);
810		fseek(newmsg, oldpos, 0);	/* reposition current message */
811		if (inch == 's')
812			printf("Message %d saved in \"%s\"\n", cmsg, fname);
813		else {
814			system(cmdbuf);
815			unlink(fname);
816			mailing = NO;
817		}
818		ask(prompt);
819	}
820}
821
822void
823gfrsub(infile)
824FILE *infile;
825{
826	off_t frompos;
827	int count;
828
829	seensubj = seenfrom = NO;
830	local = YES;
831	subj[0] = from[0] = date[0] = NULL;
832
833	/*
834	 * Is this a normal message?
835	 */
836	if (fgets(inbuf, sizeof inbuf, infile)) {
837		if (strncmp(inbuf, "From", 4)==0) {
838			/*
839			 * expected form starts with From
840			 */
841			seenfrom = YES;
842			frompos = ftell(infile);
843			ptr = from;
844			in = nxtfld(inbuf);
845			if (*in) {
846				count = sizeof(from) - 1;
847				while (*in && *in > ' ' && count-- > 0) {
848					if (*in == ':' || *in == '@' ||
849					    *in == '!')
850						local = NO;
851					*ptr++ = *in++;
852				}
853			}
854			*ptr = NULL;
855			if (*(in = nxtfld(in)))
856				strncpy(date, in, sizeof date);
857			else {
858				date[0] = '\n';
859				date[1] = NULL;
860			}
861		}
862		else {
863			/*
864			 * not the expected form
865			 */
866			fseek(infile, 0L, 0);
867			return;
868		}
869	}
870	else
871		/*
872		 * empty file ?
873		 */
874		return;
875
876	/*
877	 * look for Subject line until EOF or a blank line
878	 */
879	while (fgets(inbuf, sizeof inbuf, infile)
880	    && !(blankline = (inbuf[0] == '\n'))) {
881		/*
882		 * extract Subject line
883		 */
884		if (!seensubj && strncmp(inbuf, "Subj", 4)==0) {
885			seensubj = YES;
886			frompos = ftell(infile);
887			strncpy(subj, nxtfld(inbuf), sizeof subj);
888		}
889	}
890	if (!blankline)
891		/*
892		 * ran into EOF
893		 */
894		fseek(infile, frompos, 0);
895
896	if (!seensubj)
897		/*
898		 * for possible use with Mail
899		 */
900		strncpy(subj, "(No Subject)\n", sizeof subj);
901}
902
903char *
904nxtfld(s)
905unsigned char *s;
906{
907	if (*s) while (*s && !isspace(*s)) s++;     /* skip over this field */
908	if (*s) while (*s && isspace(*s)) s++;    /* find start of next field */
909	return (s);
910}
911