msgs.c revision 241737 
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 * 4. Neither the name of the University nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#ifndef lint
31static const char copyright[] =
32"@(#) Copyright (c) 1980, 1993\n\
33	The Regents of the University of California.  All rights reserved.\n";
34#endif /* not lint */
35
36#if 0
37#ifndef lint
38static char sccsid[] = "@(#)msgs.c	8.2 (Berkeley) 4/28/95";
39#endif /* not lint */
40#endif
41
42#include <sys/cdefs.h>
43__FBSDID("$FreeBSD: head/usr.bin/msgs/msgs.c 241737 2012-10-19 14:49:42Z ed $");
44
45/*
46 * msgs - a user bulletin board program
47 *
48 * usage:
49 *	msgs [fhlopq] [[-]number]	to read messages
50 *	msgs -s				to place messages
51 *	msgs -c [-days]			to clean up the bulletin board
52 *
53 * prompt commands are:
54 *	y	print message
55 *	n	flush message, go to next message
56 *	q	flush message, quit
57 *	p	print message, turn on 'pipe thru more' mode
58 *	P	print message, turn off 'pipe thru more' mode
59 *	-	reprint last message
60 *	s[-][<num>] [<filename>]	save message
61 *	m[-][<num>]	mail with message in temp mbox
62 *	x	exit without flushing this message
63 *	<num>	print message number <num>
64 */
65
66#define V7		/* will look for TERM in the environment */
67#define OBJECT		/* will object to messages without Subjects */
68/* #define REJECT */	/* will reject messages without Subjects
69			   (OBJECT must be defined also) */
70/* #define UNBUFFERED *//* use unbuffered output */
71
72#include <sys/param.h>
73#include <sys/stat.h>
74#include <ctype.h>
75#include <dirent.h>
76#include <err.h>
77#include <errno.h>
78#include <fcntl.h>
79#include <locale.h>
80#include <pwd.h>
81#include <setjmp.h>
82#include <termcap.h>
83#include <termios.h>
84#include <signal.h>
85#include <stdio.h>
86#include <stdlib.h>
87#include <string.h>
88#include <time.h>
89#include <unistd.h>
90#include "pathnames.h"
91
92#define	CMODE	0644		/* bounds file creation	mode */
93#define NO	0
94#define YES	1
95#define SUPERUSER	0	/* superuser uid */
96#define DAEMON		1	/* daemon uid */
97#define NLINES	24		/* default number of lines/crt screen */
98#define NDAYS	21		/* default keep time for messages */
99#define DAYS	*24*60*60	/* seconds/day */
100#define MSGSRC	".msgsrc"	/* user's rc file */
101#define BOUNDS	"bounds"	/* message bounds file */
102#define NEXT	"Next message? [yq]"
103#define MORE	"More? [ynq]"
104#define NOMORE	"(No more) [q] ?"
105
106typedef	char	bool;
107
108static FILE	*msgsrc;
109static FILE	*newmsg;
110static const char *sep = "-";
111static char	inbuf[BUFSIZ];
112static char	fname[MAXPATHLEN];
113static char	cmdbuf[MAXPATHLEN + MAXPATHLEN];
114static char	subj[128];
115static char	from[128];
116static char	date[128];
117static char	*ptr;
118static char	*in;
119static bool	local;
120static bool	ruptible;
121static bool	totty;
122static bool	seenfrom;
123static bool	seensubj;
124static bool	blankline;
125static bool	printing = NO;
126static bool	mailing = NO;
127static bool	quitit = NO;
128static bool	sending = NO;
129static bool	intrpflg = NO;
130static uid_t	uid;
131static int	msg;
132static int	prevmsg;
133static int	lct;
134static int	nlines;
135static int	Lpp = 0;
136static time_t	t;
137static time_t	keep;
138
139/* option initialization */
140static bool	hdrs = NO;
141static bool	qopt = NO;
142static bool	hush = NO;
143static bool	send_msg = NO;
144static bool	locomode = NO;
145static bool	use_pager = NO;
146static bool	clean = NO;
147static bool	lastcmd = NO;
148static jmp_buf	tstpbuf;
149
150static void	ask(const char *);
151static void	gfrsub(FILE *);
152static int	linecnt(FILE *);
153static int	next(char *);
154static char	*nxtfld(char *);
155static void	onsusp(int);
156static void	onintr(int);
157static void	prmesg(int);
158static void	usage(void);
159
160int
161main(int argc, char *argv[])
162{
163	bool newrc, already;
164	int rcfirst = 0;		/* first message to print (from .rc) */
165	int rcback = 0;			/* amount to back off of rcfirst */
166	int firstmsg = 0, nextmsg = 0, lastmsg = 0;
167	int blast = 0;
168	struct stat buf;		/* stat to check access of bounds */
169	FILE *bounds;
170	char *cp;
171
172#ifdef UNBUFFERED
173	setbuf(stdout, NULL);
174#endif
175	setlocale(LC_ALL, "");
176
177	time(&t);
178	setuid(uid = getuid());
179	ruptible = (signal(SIGINT, SIG_IGN) == SIG_DFL);
180	if (ruptible)
181		signal(SIGINT, SIG_DFL);
182
183	argc--, argv++;
184	while (argc > 0) {
185		if (isdigit(argv[0][0])) {	/* starting message # */
186			rcfirst = atoi(argv[0]);
187		}
188		else if (isdigit(argv[0][1])) {	/* backward offset */
189			rcback = atoi( &( argv[0][1] ) );
190		}
191		else {
192			ptr = *argv;
193			while (*ptr) switch (*ptr++) {
194
195			case '-':
196				break;
197
198			case 'c':
199				if (uid != SUPERUSER && uid != DAEMON)
200					errx(1,
201				"only the super-user can use the c flag");
202				clean = YES;
203				break;
204
205			case 'f':		/* silently */
206				hush = YES;
207				break;
208
209			case 'h':		/* headers only */
210				hdrs = YES;
211				break;
212
213			case 'l':		/* local msgs only */
214				locomode = YES;
215				break;
216
217			case 'o':		/* option to save last message */
218				lastcmd = YES;
219				break;
220
221			case 'p':		/* pipe thru 'more' during long msgs */
222				use_pager = YES;
223				break;
224
225			case 'q':		/* query only */
226				qopt = YES;
227				break;
228
229			case 's':		/* sending TO msgs */
230				send_msg = YES;
231				break;
232
233			default:
234				usage();
235			}
236		}
237		argc--, argv++;
238	}
239
240	/*
241	 * determine current message bounds
242	 */
243	snprintf(fname, sizeof(fname), "%s/%s", _PATH_MSGS, BOUNDS);
244
245	/*
246	 * Test access rights to the bounds file
247	 * This can be a little tricky.  if(send_msg), then
248	 * we will create it.  We assume that if(send_msg),
249	 * then you have write permission there.
250	 * Else, it better be there, or we bail.
251	 */
252	if (send_msg != YES) {
253		if (stat(fname, &buf) < 0) {
254			if (hush != YES) {
255				err(errno, "%s", fname);
256			} else {
257				exit(1);
258			}
259		}
260	}
261	bounds = fopen(fname, "r");
262
263	if (bounds != NULL) {
264		fscanf(bounds, "%d %d\n", &firstmsg, &lastmsg);
265		fclose(bounds);
266		blast = lastmsg;	/* save upper bound */
267	}
268
269	if (clean)
270		keep = t - (rcback? rcback : NDAYS) DAYS;
271
272	if (clean || bounds == NULL) {	/* relocate message bounds */
273		struct dirent *dp;
274		struct stat stbuf;
275		bool seenany = NO;
276		DIR	*dirp;
277
278		dirp = opendir(_PATH_MSGS);
279		if (dirp == NULL)
280			err(errno, "%s", _PATH_MSGS);
281
282		firstmsg = 32767;
283		lastmsg = 0;
284
285		for (dp = readdir(dirp); dp != NULL; dp = readdir(dirp)){
286			cp = dp->d_name;
287			int i = 0;
288
289			if (dp->d_ino == 0)
290				continue;
291			if (dp->d_namlen == 0)
292				continue;
293
294			if (clean)
295				snprintf(inbuf, sizeof(inbuf), "%s/%s", _PATH_MSGS, cp);
296
297			while (isdigit(*cp))
298				i = i * 10 + *cp++ - '0';
299			if (*cp)
300				continue;	/* not a message! */
301
302			if (clean) {
303				if (stat(inbuf, &stbuf) != 0)
304					continue;
305				if (stbuf.st_mtime < keep
306				    && stbuf.st_mode&S_IWRITE) {
307					unlink(inbuf);
308					continue;
309				}
310			}
311
312			if (i > lastmsg)
313				lastmsg = i;
314			if (i < firstmsg)
315				firstmsg = i;
316			seenany = YES;
317		}
318		closedir(dirp);
319
320		if (!seenany) {
321			if (blast != 0)	/* never lower the upper bound! */
322				lastmsg = blast;
323			firstmsg = lastmsg + 1;
324		}
325		else if (blast > lastmsg)
326			lastmsg = blast;
327
328		if (!send_msg) {
329			bounds = fopen(fname, "w");
330			if (bounds == NULL)
331				err(errno, "%s", fname);
332			chmod(fname, CMODE);
333			fprintf(bounds, "%d %d\n", firstmsg, lastmsg);
334			fclose(bounds);
335		}
336	}
337
338	if (send_msg) {
339		/*
340		 * Send mode - place msgs in _PATH_MSGS
341		 */
342		bounds = fopen(fname, "w");
343		if (bounds == NULL)
344			err(errno, "%s", fname);
345
346		nextmsg = lastmsg + 1;
347		snprintf(fname, sizeof(fname), "%s/%d", _PATH_MSGS, nextmsg);
348		newmsg = fopen(fname, "w");
349		if (newmsg == NULL)
350			err(errno, "%s", fname);
351		chmod(fname, CMODE);
352
353		fprintf(bounds, "%d %d\n", firstmsg, nextmsg);
354		fclose(bounds);
355
356		sending = YES;
357		if (ruptible)
358			signal(SIGINT, onintr);
359
360		if (isatty(fileno(stdin))) {
361			ptr = getpwuid(uid)->pw_name;
362			printf("Message %d:\nFrom %s %sSubject: ",
363				nextmsg, ptr, ctime(&t));
364			fflush(stdout);
365			fgets(inbuf, sizeof inbuf, stdin);
366			putchar('\n');
367			fflush(stdout);
368			fprintf(newmsg, "From %s %sSubject: %s\n",
369				ptr, ctime(&t), inbuf);
370			blankline = seensubj = YES;
371		}
372		else
373			blankline = seensubj = NO;
374		for (;;) {
375			fgets(inbuf, sizeof inbuf, stdin);
376			if (feof(stdin) || ferror(stdin))
377				break;
378			blankline = (blankline || (inbuf[0] == '\n'));
379			seensubj = (seensubj || (!blankline && (strncmp(inbuf, "Subj", 4) == 0)));
380			fputs(inbuf, newmsg);
381		}
382#ifdef OBJECT
383		if (!seensubj) {
384			printf("NOTICE: Messages should have a Subject field!\n");
385#ifdef REJECT
386			unlink(fname);
387#endif
388			exit(1);
389		}
390#endif
391		exit(ferror(stdin));
392	}
393	if (clean)
394		exit(0);
395
396	/*
397	 * prepare to display messages
398	 */
399	totty = (isatty(fileno(stdout)) != 0);
400	use_pager = use_pager && totty;
401
402	if ((cp = getenv("HOME")) == NULL || *cp == '\0') {
403		fprintf(stderr, "Error, no home directory!\n");
404		exit(1);
405	}
406	snprintf(fname, sizeof(fname), "%s/%s", cp, MSGSRC);
407	msgsrc = fopen(fname, "r");
408	if (msgsrc) {
409		newrc = NO;
410		fscanf(msgsrc, "%d\n", &nextmsg);
411		fclose(msgsrc);
412		if (nextmsg > lastmsg+1) {
413			printf("Warning: bounds have been reset (%d, %d)\n",
414				firstmsg, lastmsg);
415			truncate(fname, (off_t)0);
416			newrc = YES;
417		}
418		else if (!rcfirst)
419			rcfirst = nextmsg - rcback;
420	}
421	else
422		newrc = YES;
423	msgsrc = fopen(fname, "r+");
424	if (msgsrc == NULL)
425		msgsrc = fopen(fname, "w");
426	if (msgsrc == NULL)
427		err(errno, "%s", fname);
428	if (rcfirst) {
429		if (rcfirst > lastmsg+1) {
430			printf("Warning: the last message is number %d.\n",
431				lastmsg);
432			rcfirst = nextmsg;
433		}
434		if (rcfirst > firstmsg)
435			firstmsg = rcfirst;	/* don't set below first msg */
436	}
437	if (newrc) {
438		nextmsg = firstmsg;
439		rewind(msgsrc);
440		fprintf(msgsrc, "%d\n", nextmsg);
441		fflush(msgsrc);
442	}
443
444#ifdef V7
445	if (totty) {
446		struct winsize win;
447		if (ioctl(fileno(stdout), TIOCGWINSZ, &win) != -1)
448			Lpp = win.ws_row;
449		if (Lpp <= 0) {
450			if (tgetent(inbuf, getenv("TERM")) <= 0
451			    || (Lpp = tgetnum("li")) <= 0) {
452				Lpp = NLINES;
453			}
454		}
455	}
456#endif
457	Lpp -= 6;	/* for headers, etc. */
458
459	already = NO;
460	prevmsg = firstmsg;
461	printing = YES;
462	if (ruptible)
463		signal(SIGINT, onintr);
464
465	/*
466	 * Main program loop
467	 */
468	for (msg = firstmsg; msg <= lastmsg; msg++) {
469
470		snprintf(fname, sizeof(fname), "%s/%d", _PATH_MSGS, msg);
471		newmsg = fopen(fname, "r");
472		if (newmsg == NULL)
473			continue;
474
475		gfrsub(newmsg);		/* get From and Subject fields */
476		if (locomode && !local) {
477			fclose(newmsg);
478			continue;
479		}
480
481		if (qopt) {	/* This has to be located here */
482			printf("There are new messages.\n");
483			exit(0);
484		}
485
486		if (already && !hdrs)
487			putchar('\n');
488
489		/*
490		 * Print header
491		 */
492		if (totty)
493			signal(SIGTSTP, onsusp);
494		(void) setjmp(tstpbuf);
495		already = YES;
496		nlines = 2;
497		if (seenfrom) {
498			printf("Message %d:\nFrom %s %s", msg, from, date);
499			nlines++;
500		}
501		if (seensubj) {
502			printf("Subject: %s", subj);
503			nlines++;
504		}
505		else {
506			if (seenfrom) {
507				putchar('\n');
508				nlines++;
509			}
510			while (nlines < 6
511			    && fgets(inbuf, sizeof inbuf, newmsg)
512			    && inbuf[0] != '\n') {
513				fputs(inbuf, stdout);
514				nlines++;
515			}
516		}
517
518		lct = linecnt(newmsg);
519		if (lct)
520			printf("(%d%sline%s) ", lct, seensubj? " " : " more ",
521			    (lct == 1) ? "" : "s");
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				/* FALLTHROUGH */
543			case 'X':
544				exit(0);
545				/* NOTREACHED */
546
547			case 'q':
548				/* FALLTHROUGH */
549			case 'Q':
550				quitit = YES;
551				printf("--Postponed--\n");
552				exit(0);
553				/* NOTREACHED */
554
555			case 'n':
556				/* FALLTHROUGH */
557			case 'N':
558				if (msg >= nextmsg) sep = "Flushed";
559				prevmsg = msg;
560				break;
561
562			case 'p':
563				/* FALLTHROUGH */
564			case 'P':
565				use_pager = (*in++ == 'p');
566				/* FALLTHROUGH */
567			case '\n':
568				/* FALLTHROUGH */
569			case 'y':
570			default:
571				if (*in == '-') {
572					msg = prevmsg-1;
573					sep = "replay";
574					break;
575				}
576				if (isdigit(*in)) {
577					msg = next(in);
578					sep = in;
579					break;
580				}
581
582				prmesg(nlines + lct + (seensubj? 1 : 0));
583				prevmsg = msg;
584
585		}
586
587		printf("--%s--\n", sep);
588		sep = "-";
589		if (msg >= nextmsg) {
590			nextmsg = msg + 1;
591			rewind(msgsrc);
592			fprintf(msgsrc, "%d\n", nextmsg);
593			fflush(msgsrc);
594		}
595		if (newmsg)
596			fclose(newmsg);
597		if (quitit)
598			break;
599	}
600
601	/*
602	 * Make sure .rc file gets updated
603	 */
604	if (--msg >= nextmsg) {
605		nextmsg = msg + 1;
606		rewind(msgsrc);
607		fprintf(msgsrc, "%d\n", nextmsg);
608		fflush(msgsrc);
609	}
610	if (already && !quitit && lastcmd && totty) {
611		/*
612		 * save or reply to last message?
613		 */
614		msg = prevmsg;
615		ask(NOMORE);
616		if (inbuf[0] == '-' || isdigit(inbuf[0]))
617			goto cmnd;
618	}
619	if (!(already || hush || qopt))
620		printf("No new messages.\n");
621	exit(0);
622	/* NOTREACHED */
623}
624
625static void
626usage(void)
627{
628	fprintf(stderr, "usage: msgs [fhlopq] [[-]number]\n");
629	exit(1);
630}
631
632static void
633prmesg(int length)
634{
635	FILE *outf;
636	char *env_pager;
637
638	if (use_pager && length > Lpp) {
639		signal(SIGPIPE, SIG_IGN);
640		signal(SIGQUIT, SIG_IGN);
641		if ((env_pager = getenv("PAGER")) == NULL) {
642			snprintf(cmdbuf, sizeof(cmdbuf), _PATH_PAGER, Lpp);
643		} else {
644			snprintf(cmdbuf, sizeof(cmdbuf), "%s", env_pager);
645		}
646		outf = popen(cmdbuf, "w");
647		if (!outf)
648			outf = stdout;
649		else
650			setbuf(outf, (char *)NULL);
651	}
652	else
653		outf = stdout;
654
655	if (seensubj)
656		putc('\n', outf);
657
658	while (fgets(inbuf, sizeof inbuf, newmsg)) {
659		fputs(inbuf, outf);
660		if (ferror(outf)) {
661			clearerr(outf);
662			break;
663		}
664	}
665
666	if (outf != stdout) {
667		pclose(outf);
668		signal(SIGPIPE, SIG_DFL);
669		signal(SIGQUIT, SIG_DFL);
670	}
671	else {
672		fflush(stdout);
673	}
674
675	/* force wait on output */
676	tcdrain(fileno(stdout));
677}
678
679static void
680onintr(int unused __unused)
681{
682	signal(SIGINT, onintr);
683	if (mailing)
684		unlink(fname);
685	if (sending) {
686		unlink(fname);
687		puts("--Killed--");
688		exit(1);
689	}
690	if (printing) {
691		putchar('\n');
692		if (hdrs)
693			exit(0);
694		sep = "Interrupt";
695		if (newmsg)
696			fseeko(newmsg, (off_t)0, SEEK_END);
697		intrpflg = YES;
698	}
699}
700
701/*
702 * We have just gotten a susp.  Suspend and prepare to resume.
703 */
704static void
705onsusp(int unused __unused)
706{
707	signal(SIGTSTP, SIG_DFL);
708	sigsetmask(0);
709	kill(0, SIGTSTP);
710	signal(SIGTSTP, onsusp);
711	if (!mailing)
712		longjmp(tstpbuf, 0);
713}
714
715static int
716linecnt(FILE *f)
717{
718	off_t oldpos = ftello(f);
719	int l = 0;
720	char lbuf[BUFSIZ];
721
722	while (fgets(lbuf, sizeof lbuf, f))
723		l++;
724	clearerr(f);
725	fseeko(f, oldpos, SEEK_SET);
726	return (l);
727}
728
729static int
730next(char *buf)
731{
732	int i;
733	sscanf(buf, "%d", &i);
734	sprintf(buf, "Goto %d", i);
735	return(--i);
736}
737
738static void
739ask(const char *prompt)
740{
741	char	inch;
742	int	n, cmsg, fd;
743	off_t	oldpos;
744	FILE	*cpfrom, *cpto;
745
746	printf("%s ", prompt);
747	fflush(stdout);
748	intrpflg = NO;
749	(void) fgets(inbuf, sizeof inbuf, stdin);
750	if ((n = strlen(inbuf)) > 0 && inbuf[n - 1] == '\n')
751		inbuf[n - 1] = '\0';
752	if (intrpflg)
753		inbuf[0] = 'x';
754
755	/*
756	 * Handle 'mail' and 'save' here.
757	 */
758	if ((inch = inbuf[0]) == 's' || inch == 'm') {
759		if (inbuf[1] == '-')
760			cmsg = prevmsg;
761		else if (isdigit(inbuf[1]))
762			cmsg = atoi(&inbuf[1]);
763		else
764			cmsg = msg;
765		snprintf(fname, sizeof(fname), "%s/%d", _PATH_MSGS, cmsg);
766
767		oldpos = ftello(newmsg);
768
769		cpfrom = fopen(fname, "r");
770		if (!cpfrom) {
771			printf("Message %d not found\n", cmsg);
772			ask (prompt);
773			return;
774		}
775
776		if (inch == 's') {
777			in = nxtfld(inbuf);
778			if (*in) {
779				for (n=0; in[n] > ' '; n++) { /* sizeof fname? */
780					fname[n] = in[n];
781				}
782				fname[n] = '\0';
783			}
784			else
785				strcpy(fname, "Messages");
786			fd = open(fname, O_RDWR|O_EXCL|O_CREAT|O_APPEND);
787		}
788		else {
789			strcpy(fname, _PATH_TMP);
790			fd = mkstemp(fname);
791			if (fd != -1) {
792				snprintf(cmdbuf, sizeof(cmdbuf), _PATH_MAIL,
793				    fname);
794				mailing = YES;
795			}
796		}
797		if (fd == -1 || (cpto = fdopen(fd, "a")) == NULL) {
798			if (fd != -1)
799				close(fd);
800			warn("%s", fname);
801			mailing = NO;
802			fseeko(newmsg, oldpos, SEEK_SET);
803			ask(prompt);
804			return;
805		}
806
807		while ((n = fread(inbuf, 1, sizeof inbuf, cpfrom)))
808			fwrite(inbuf, 1, n, cpto);
809
810		fclose(cpfrom);
811		fclose(cpto);
812		fseeko(newmsg, oldpos, SEEK_SET);/* reposition current message */
813		if (inch == 's')
814			printf("Message %d saved in \"%s\"\n", cmsg, fname);
815		else {
816			system(cmdbuf);
817			unlink(fname);
818			mailing = NO;
819		}
820		ask(prompt);
821	}
822}
823
824static void
825gfrsub(FILE *infile)
826{
827	off_t frompos;
828	int count;
829
830	seensubj = seenfrom = NO;
831	local = YES;
832	subj[0] = from[0] = date[0] = '\0';
833
834	/*
835	 * Is this a normal message?
836	 */
837	if (fgets(inbuf, sizeof inbuf, infile)) {
838		if (strncmp(inbuf, "From", 4)==0) {
839			/*
840			 * expected form starts with From
841			 */
842			seenfrom = YES;
843			frompos = ftello(infile);
844			ptr = from;
845			in = nxtfld(inbuf);
846			if (*in) {
847				count = sizeof(from) - 1;
848				while (*in && *in > ' ' && count-- > 0) {
849					if (*in == ':' || *in == '@' ||
850					    *in == '!')
851						local = NO;
852					*ptr++ = *in++;
853				}
854			}
855			*ptr = '\0';
856			if (*(in = nxtfld(in)))
857				strncpy(date, in, sizeof date);
858			else {
859				date[0] = '\n';
860				date[1] = '\0';
861			}
862		}
863		else {
864			/*
865			 * not the expected form
866			 */
867			rewind(infile);
868			return;
869		}
870	}
871	else
872		/*
873		 * empty file ?
874		 */
875		return;
876
877	/*
878	 * look for Subject line until EOF or a blank line
879	 */
880	while (fgets(inbuf, sizeof inbuf, infile)
881	    && !(blankline = (inbuf[0] == '\n'))) {
882		/*
883		 * extract Subject line
884		 */
885		if (!seensubj && strncmp(inbuf, "Subj", 4)==0) {
886			seensubj = YES;
887			frompos = ftello(infile);
888			strncpy(subj, nxtfld(inbuf), sizeof subj);
889		}
890	}
891	if (!blankline)
892		/*
893		 * ran into EOF
894		 */
895		fseeko(infile, frompos, SEEK_SET);
896
897	if (!seensubj)
898		/*
899		 * for possible use with Mail
900		 */
901		strncpy(subj, "(No Subject)\n", sizeof subj);
902}
903
904static char *
905nxtfld(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