head.c revision 74769 
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
35#if 0
36static char sccsid[] = "@(#)head.c	8.1 (Berkeley) 6/6/93";
37#endif
38static const char rcsid[] =
39  "$FreeBSD: head/usr.bin/mail/head.c 74769 2001-03-25 04:57:05Z mikeh $";
40#endif /* not lint */
41
42#include "rcv.h"
43#include "extern.h"
44
45/*
46 * Mail -- a mail program
47 *
48 * Routines for processing and detecting headlines.
49 */
50
51/*
52 * See if the passed line buffer is a mail header.
53 * Return true if yes.  Note the extreme pains to
54 * accomodate all funny formats.
55 */
56int
57ishead(linebuf)
58	char linebuf[];
59{
60	struct headline hl;
61	char parbuf[BUFSIZ];
62
63	if (strncmp(linebuf, "From ", 5))
64		return (0);
65	parse(linebuf, &hl, parbuf);
66	if (hl.l_from == NOSTR || hl.l_date == NOSTR) {
67		fail(linebuf, "No from or date field");
68		return (0);
69	}
70	if (!isdate(hl.l_date)) {
71		fail(linebuf, "Date field not legal date");
72		return (0);
73	}
74	/*
75	 * I guess we got it!
76	 */
77	return (1);
78}
79
80/*ARGSUSED*/
81void
82fail(linebuf, reason)
83	char linebuf[], reason[];
84{
85
86	/*
87	if (value("debug") == NOSTR)
88		return;
89	fprintf(stderr, "\"%s\"\nnot a header because %s\n", linebuf, reason);
90	*/
91}
92
93/*
94 * Split a headline into its useful components.
95 * Copy the line into dynamic string space, then set
96 * pointers into the copied line in the passed headline
97 * structure.  Actually, it scans.
98 */
99void
100parse(line, hl, pbuf)
101	char line[], pbuf[];
102	register struct headline *hl;
103{
104	register char *cp;
105	char *sp;
106	char word[LINESIZE];
107
108	hl->l_from = NOSTR;
109	hl->l_tty = NOSTR;
110	hl->l_date = NOSTR;
111	cp = line;
112	sp = pbuf;
113	/*
114	 * Skip over "From" first.
115	 */
116	cp = nextword(cp, word);
117	cp = nextword(cp, word);
118	if (*word)
119		hl->l_from = copyin(word, &sp);
120	if (cp != NOSTR && cp[0] == 't' && cp[1] == 't' && cp[2] == 'y') {
121		cp = nextword(cp, word);
122		hl->l_tty = copyin(word, &sp);
123	}
124	if (cp != NOSTR)
125		hl->l_date = copyin(cp, &sp);
126}
127
128/*
129 * Copy the string on the left into the string on the right
130 * and bump the right (reference) string pointer by the length.
131 * Thus, dynamically allocate space in the right string, copying
132 * the left string into it.
133 */
134char *
135copyin(src, space)
136	register char *src;
137	char **space;
138{
139	register char *cp;
140	char *top;
141
142	top = cp = *space;
143	while (*cp++ = *src++)
144		;
145	*space = cp;
146	return (top);
147}
148
149/*
150 * Test to see if the passed string is a ctime(3) generated
151 * date string as documented in the manual.  The template
152 * below is used as the criterion of correctness.
153 * Also, we check for a possible trailing time zone using
154 * the tmztype template.
155 */
156
157/*
158 * 'A'	An upper case char
159 * 'a'	A lower case char
160 * ' '	A space
161 * '0'	A digit
162 * 'O'	An optional digit or space
163 * ':'	A colon
164 * 'N'	A new line
165 */
166char ctype[] = "Aaa Aaa O0 00:00:00 0000";
167char tmztype[] = "Aaa Aaa O0 00:00:00 AAA 0000";
168
169int
170isdate(date)
171	char date[];
172{
173
174	return cmatch(date, ctype) || cmatch(date, tmztype);
175}
176
177/*
178 * Match the given string (cp) against the given template (tp).
179 * Return 1 if they match, 0 if they don't
180 */
181int
182cmatch(cp, tp)
183	register char *cp, *tp;
184{
185
186	while (*cp && *tp)
187		switch (*tp++) {
188		case 'a':
189			if (!islower(*cp++))
190				return 0;
191			break;
192		case 'A':
193			if (!isupper(*cp++))
194				return 0;
195			break;
196		case ' ':
197			if (*cp++ != ' ')
198				return 0;
199			break;
200		case '0':
201			if (!isdigit(*cp++))
202				return 0;
203			break;
204		case 'O':
205			if (*cp != ' ' && !isdigit(*cp))
206				return 0;
207			cp++;
208			break;
209		case ':':
210			if (*cp++ != ':')
211				return 0;
212			break;
213		case 'N':
214			if (*cp++ != '\n')
215				return 0;
216			break;
217		}
218	if (*cp || *tp)
219		return 0;
220	return (1);
221}
222
223/*
224 * Collect a liberal (space, tab delimited) word into the word buffer
225 * passed.  Also, return a pointer to the next word following that,
226 * or NOSTR if none follow.
227 */
228char *
229nextword(wp, wbuf)
230	register char *wp, *wbuf;
231{
232	register c;
233
234	if (wp == NOSTR) {
235		*wbuf = 0;
236		return (NOSTR);
237	}
238	while ((c = *wp++) && c != ' ' && c != '\t') {
239		*wbuf++ = c;
240		if (c == '"') {
241 			while ((c = *wp++) && c != '"')
242 				*wbuf++ = c;
243 			if (c == '"')
244 				*wbuf++ = c;
245			else
246				wp--;
247 		}
248	}
249	*wbuf = '\0';
250	for (; c == ' ' || c == '\t'; c = *wp++)
251		;
252	if (c == 0)
253		return (NOSTR);
254	return (wp - 1);
255}
256