xref: /netbsd-src/usr.bin/mail/head.c (revision e9d867ef5010fbab8d48045c13025636f5cd7479)
1 /*
2  * Copyright (c) 1980 Regents of the University of California.
3  * 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 /*static char sccsid[] = "from: @(#)head.c	5.7 (Berkeley) 6/1/90";*/
36 static char rcsid[] = "$Id: head.c,v 1.2 1993/08/01 18:13:04 mycroft Exp $";
37 #endif /* not lint */
38 
39 #include "rcv.h"
40 
41 /*
42  * Mail -- a mail program
43  *
44  * Routines for processing and detecting headlines.
45  */
46 
47 /*
48  * See if the passed line buffer is a mail header.
49  * Return true if yes.  Note the extreme pains to
50  * accomodate all funny formats.
51  */
52 ishead(linebuf)
53 	char linebuf[];
54 {
55 	register char *cp;
56 	struct headline hl;
57 	char parbuf[BUFSIZ];
58 
59 	cp = linebuf;
60 	if (*cp++ != 'F' || *cp++ != 'r' || *cp++ != 'o' || *cp++ != 'm' ||
61 	    *cp++ != ' ')
62 		return (0);
63 	parse(linebuf, &hl, parbuf);
64 	if (hl.l_from == NOSTR || hl.l_date == NOSTR) {
65 		fail(linebuf, "No from or date field");
66 		return (0);
67 	}
68 	if (!isdate(hl.l_date)) {
69 		fail(linebuf, "Date field not legal date");
70 		return (0);
71 	}
72 	/*
73 	 * I guess we got it!
74 	 */
75 	return (1);
76 }
77 
78 /*ARGSUSED*/
79 fail(linebuf, reason)
80 	char linebuf[], reason[];
81 {
82 
83 	/*
84 	if (value("debug") == NOSTR)
85 		return;
86 	fprintf(stderr, "\"%s\"\nnot a header because %s\n", linebuf, reason);
87 	*/
88 }
89 
90 /*
91  * Split a headline into its useful components.
92  * Copy the line into dynamic string space, then set
93  * pointers into the copied line in the passed headline
94  * structure.  Actually, it scans.
95  */
96 parse(line, hl, pbuf)
97 	char line[], pbuf[];
98 	register struct headline *hl;
99 {
100 	register char *cp;
101 	char *sp;
102 	char word[LINESIZE];
103 
104 	hl->l_from = NOSTR;
105 	hl->l_tty = NOSTR;
106 	hl->l_date = NOSTR;
107 	cp = line;
108 	sp = pbuf;
109 	/*
110 	 * Skip over "From" first.
111 	 */
112 	cp = nextword(cp, word);
113 	cp = nextword(cp, word);
114 	if (*word)
115 		hl->l_from = copyin(word, &sp);
116 	if (cp != NOSTR && cp[0] == 't' && cp[1] == 't' && cp[2] == 'y') {
117 		cp = nextword(cp, word);
118 		hl->l_tty = copyin(word, &sp);
119 	}
120 	if (cp != NOSTR)
121 		hl->l_date = copyin(cp, &sp);
122 }
123 
124 /*
125  * Copy the string on the left into the string on the right
126  * and bump the right (reference) string pointer by the length.
127  * Thus, dynamically allocate space in the right string, copying
128  * the left string into it.
129  */
130 char *
131 copyin(src, space)
132 	register char *src;
133 	char **space;
134 {
135 	register char *cp;
136 	char *top;
137 
138 	top = cp = *space;
139 	while (*cp++ = *src++)
140 		;
141 	*space = cp;
142 	return (top);
143 }
144 
145 /*
146  * Test to see if the passed string is a ctime(3) generated
147  * date string as documented in the manual.  The template
148  * below is used as the criterion of correctness.
149  * Also, we check for a possible trailing time zone using
150  * the tmztype template.
151  */
152 
153 /*
154  * 'A'	An upper case char
155  * 'a'	A lower case char
156  * ' '	A space
157  * '0'	A digit
158  * 'O'	An optional digit or space
159  * ':'	A colon
160  * 'N'	A new line
161  */
162 char ctype[] = "Aaa Aaa O0 00:00:00 0000";
163 char tmztype[] = "Aaa Aaa O0 00:00:00 AAA 0000";
164 
165 isdate(date)
166 	char date[];
167 {
168 
169 	return cmatch(date, ctype) || cmatch(date, tmztype);
170 }
171 
172 /*
173  * Match the given string (cp) against the given template (tp).
174  * Return 1 if they match, 0 if they don't
175  */
176 cmatch(cp, tp)
177 	register char *cp, *tp;
178 {
179 
180 	while (*cp && *tp)
181 		switch (*tp++) {
182 		case 'a':
183 			if (!islower(*cp++))
184 				return 0;
185 			break;
186 		case 'A':
187 			if (!isupper(*cp++))
188 				return 0;
189 			break;
190 		case ' ':
191 			if (*cp++ != ' ')
192 				return 0;
193 			break;
194 		case '0':
195 			if (!isdigit(*cp++))
196 				return 0;
197 			break;
198 		case 'O':
199 			if (*cp != ' ' && !isdigit(*cp))
200 				return 0;
201 			cp++;
202 			break;
203 		case ':':
204 			if (*cp++ != ':')
205 				return 0;
206 			break;
207 		case 'N':
208 			if (*cp++ != '\n')
209 				return 0;
210 			break;
211 		}
212 	if (*cp || *tp)
213 		return 0;
214 	return (1);
215 }
216 
217 /*
218  * Collect a liberal (space, tab delimited) word into the word buffer
219  * passed.  Also, return a pointer to the next word following that,
220  * or NOSTR if none follow.
221  */
222 char *
223 nextword(wp, wbuf)
224 	register char *wp, *wbuf;
225 {
226 	register c;
227 
228 	if (wp == NOSTR) {
229 		*wbuf = 0;
230 		return (NOSTR);
231 	}
232 	while ((c = *wp++) && c != ' ' && c != '\t') {
233 		*wbuf++ = c;
234 		if (c == '"') {
235  			while ((c = *wp++) && c != '"')
236  				*wbuf++ = c;
237  			if (c == '"')
238  				*wbuf++ = c;
239 			else
240 				wp--;
241  		}
242 	}
243 	*wbuf = '\0';
244 	for (; c == ' ' || c == '\t'; c = *wp++)
245 		;
246 	if (c == 0)
247 		return (NOSTR);
248 	return (wp - 1);
249 }
250