xref: /netbsd-src/usr.bin/mail/head.c (revision 76dfffe33547c37f8bdd446e3e4ab0f3c16cea4b)
1 /*	$NetBSD: head.c,v 1.5 1996/06/08 19:48:26 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 1980, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)head.c	8.1 (Berkeley) 6/6/93";
39 #else
40 static char rcsid[] = "$NetBSD: head.c,v 1.5 1996/06/08 19:48:26 christos Exp $";
41 #endif
42 #endif /* not lint */
43 
44 #include "rcv.h"
45 #include "extern.h"
46 
47 /*
48  * Mail -- a mail program
49  *
50  * Routines for processing and detecting headlines.
51  */
52 
53 /*
54  * See if the passed line buffer is a mail header.
55  * Return true if yes.  Note the extreme pains to
56  * accomodate all funny formats.
57  */
58 int
59 ishead(linebuf)
60 	char linebuf[];
61 {
62 	register char *cp;
63 	struct headline hl;
64 	char parbuf[BUFSIZ];
65 
66 	cp = linebuf;
67 	if (*cp++ != 'F' || *cp++ != 'r' || *cp++ != 'o' || *cp++ != 'm' ||
68 	    *cp++ != ' ')
69 		return (0);
70 	parse(linebuf, &hl, parbuf);
71 	if (hl.l_from == NOSTR || hl.l_date == NOSTR) {
72 		fail(linebuf, "No from or date field");
73 		return (0);
74 	}
75 	if (!isdate(hl.l_date)) {
76 		fail(linebuf, "Date field not legal date");
77 		return (0);
78 	}
79 	/*
80 	 * I guess we got it!
81 	 */
82 	return (1);
83 }
84 
85 /*ARGSUSED*/
86 void
87 fail(linebuf, reason)
88 	char linebuf[], reason[];
89 {
90 
91 	/*
92 	if (value("debug") == NOSTR)
93 		return;
94 	fprintf(stderr, "\"%s\"\nnot a header because %s\n", linebuf, reason);
95 	*/
96 }
97 
98 /*
99  * Split a headline into its useful components.
100  * Copy the line into dynamic string space, then set
101  * pointers into the copied line in the passed headline
102  * structure.  Actually, it scans.
103  */
104 void
105 parse(line, hl, pbuf)
106 	char line[], pbuf[];
107 	register struct headline *hl;
108 {
109 	register char *cp;
110 	char *sp;
111 	char word[LINESIZE];
112 
113 	hl->l_from = NOSTR;
114 	hl->l_tty = NOSTR;
115 	hl->l_date = NOSTR;
116 	cp = line;
117 	sp = pbuf;
118 	/*
119 	 * Skip over "From" first.
120 	 */
121 	cp = nextword(cp, word);
122 	cp = nextword(cp, word);
123 	if (*word)
124 		hl->l_from = copyin(word, &sp);
125 	if (cp != NOSTR && cp[0] == 't' && cp[1] == 't' && cp[2] == 'y') {
126 		cp = nextword(cp, word);
127 		hl->l_tty = copyin(word, &sp);
128 	}
129 	if (cp != NOSTR)
130 		hl->l_date = copyin(cp, &sp);
131 }
132 
133 /*
134  * Copy the string on the left into the string on the right
135  * and bump the right (reference) string pointer by the length.
136  * Thus, dynamically allocate space in the right string, copying
137  * the left string into it.
138  */
139 char *
140 copyin(src, space)
141 	register char *src;
142 	char **space;
143 {
144 	register char *cp;
145 	char *top;
146 
147 	top = cp = *space;
148 	while ((*cp++ = *src++) != '\0')
149 		;
150 	*space = cp;
151 	return (top);
152 }
153 
154 /*
155  * Test to see if the passed string is a ctime(3) generated
156  * date string as documented in the manual.  The template
157  * below is used as the criterion of correctness.
158  * Also, we check for a possible trailing time zone using
159  * the tmztype template.
160  */
161 
162 /*
163  * 'A'	An upper case char
164  * 'a'	A lower case char
165  * ' '	A space
166  * '0'	A digit
167  * 'O'	An optional digit or space
168  * ':'	A colon
169  * 'N'	A new line
170  */
171 char ctype[] = "Aaa Aaa O0 00:00:00 0000";
172 char ctype_without_secs[] = "Aaa Aaa O0 00:00 0000";
173 char tmztype[] = "Aaa Aaa O0 00:00:00 AAA 0000";
174 char tmztype_without_secs[] = "Aaa Aaa O0 00:00 AAA 0000";
175 
176 int
177 isdate(date)
178 	char date[];
179 {
180 
181 	return cmatch(date, ctype_without_secs) ||
182 	       cmatch(date, tmztype_without_secs) ||
183 	       cmatch(date, ctype) || cmatch(date, tmztype);
184 }
185 
186 /*
187  * Match the given string (cp) against the given template (tp).
188  * Return 1 if they match, 0 if they don't
189  */
190 int
191 cmatch(cp, tp)
192 	register char *cp, *tp;
193 {
194 
195 	while (*cp && *tp)
196 		switch (*tp++) {
197 		case 'a':
198 			if (!islower(*cp++))
199 				return 0;
200 			break;
201 		case 'A':
202 			if (!isupper(*cp++))
203 				return 0;
204 			break;
205 		case ' ':
206 			if (*cp++ != ' ')
207 				return 0;
208 			break;
209 		case '0':
210 			if (!isdigit(*cp++))
211 				return 0;
212 			break;
213 		case 'O':
214 			if (*cp != ' ' && !isdigit(*cp))
215 				return 0;
216 			cp++;
217 			break;
218 		case ':':
219 			if (*cp++ != ':')
220 				return 0;
221 			break;
222 		case 'N':
223 			if (*cp++ != '\n')
224 				return 0;
225 			break;
226 		}
227 	if (*cp || *tp)
228 		return 0;
229 	return (1);
230 }
231 
232 /*
233  * Collect a liberal (space, tab delimited) word into the word buffer
234  * passed.  Also, return a pointer to the next word following that,
235  * or NOSTR if none follow.
236  */
237 char *
238 nextword(wp, wbuf)
239 	register char *wp, *wbuf;
240 {
241 	register c;
242 
243 	if (wp == NOSTR) {
244 		*wbuf = 0;
245 		return (NOSTR);
246 	}
247 	while ((c = *wp++) && c != ' ' && c != '\t') {
248 		*wbuf++ = c;
249 		if (c == '"') {
250  			while ((c = *wp++) && c != '"')
251  				*wbuf++ = c;
252  			if (c == '"')
253  				*wbuf++ = c;
254 			else
255 				wp--;
256  		}
257 	}
258 	*wbuf = '\0';
259 	for (; c == ' ' || c == '\t'; c = *wp++)
260 		;
261 	if (c == 0)
262 		return (NOSTR);
263 	return (wp - 1);
264 }
265