xref: /netbsd-src/usr.bin/mail/head.c (revision ce63d6c20fc4ec8ddc95c84bb229e3c4ecf82b69)
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[] = "@(#)head.c	5.7 (Berkeley) 6/1/90";
36 #endif /* not lint */
37 
38 #include "rcv.h"
39 
40 /*
41  * Mail -- a mail program
42  *
43  * Routines for processing and detecting headlines.
44  */
45 
46 /*
47  * See if the passed line buffer is a mail header.
48  * Return true if yes.  Note the extreme pains to
49  * accomodate all funny formats.
50  */
51 ishead(linebuf)
52 	char linebuf[];
53 {
54 	register char *cp;
55 	struct headline hl;
56 	char parbuf[BUFSIZ];
57 
58 	cp = linebuf;
59 	if (*cp++ != 'F' || *cp++ != 'r' || *cp++ != 'o' || *cp++ != 'm' ||
60 	    *cp++ != ' ')
61 		return (0);
62 	parse(linebuf, &hl, parbuf);
63 	if (hl.l_from == NOSTR || hl.l_date == NOSTR) {
64 		fail(linebuf, "No from or date field");
65 		return (0);
66 	}
67 	if (!isdate(hl.l_date)) {
68 		fail(linebuf, "Date field not legal date");
69 		return (0);
70 	}
71 	/*
72 	 * I guess we got it!
73 	 */
74 	return (1);
75 }
76 
77 /*ARGSUSED*/
78 fail(linebuf, reason)
79 	char linebuf[], reason[];
80 {
81 
82 	/*
83 	if (value("debug") == NOSTR)
84 		return;
85 	fprintf(stderr, "\"%s\"\nnot a header because %s\n", linebuf, reason);
86 	*/
87 }
88 
89 /*
90  * Split a headline into its useful components.
91  * Copy the line into dynamic string space, then set
92  * pointers into the copied line in the passed headline
93  * structure.  Actually, it scans.
94  */
95 parse(line, hl, pbuf)
96 	char line[], pbuf[];
97 	register struct headline *hl;
98 {
99 	register char *cp;
100 	char *sp;
101 	char word[LINESIZE];
102 
103 	hl->l_from = NOSTR;
104 	hl->l_tty = NOSTR;
105 	hl->l_date = NOSTR;
106 	cp = line;
107 	sp = pbuf;
108 	/*
109 	 * Skip over "From" first.
110 	 */
111 	cp = nextword(cp, word);
112 	cp = nextword(cp, word);
113 	if (*word)
114 		hl->l_from = copyin(word, &sp);
115 	if (cp != NOSTR && cp[0] == 't' && cp[1] == 't' && cp[2] == 'y') {
116 		cp = nextword(cp, word);
117 		hl->l_tty = copyin(word, &sp);
118 	}
119 	if (cp != NOSTR)
120 		hl->l_date = copyin(cp, &sp);
121 }
122 
123 /*
124  * Copy the string on the left into the string on the right
125  * and bump the right (reference) string pointer by the length.
126  * Thus, dynamically allocate space in the right string, copying
127  * the left string into it.
128  */
129 char *
130 copyin(src, space)
131 	register char *src;
132 	char **space;
133 {
134 	register char *cp;
135 	char *top;
136 
137 	top = cp = *space;
138 	while (*cp++ = *src++)
139 		;
140 	*space = cp;
141 	return (top);
142 }
143 
144 /*
145  * Test to see if the passed string is a ctime(3) generated
146  * date string as documented in the manual.  The template
147  * below is used as the criterion of correctness.
148  * Also, we check for a possible trailing time zone using
149  * the tmztype template.
150  */
151 
152 /*
153  * 'A'	An upper case char
154  * 'a'	A lower case char
155  * ' '	A space
156  * '0'	A digit
157  * 'O'	An optional digit or space
158  * ':'	A colon
159  * 'N'	A new line
160  */
161 char ctype[] = "Aaa Aaa O0 00:00:00 0000";
162 char tmztype[] = "Aaa Aaa O0 00:00:00 AAA 0000";
163 
164 isdate(date)
165 	char date[];
166 {
167 
168 	return cmatch(date, ctype) || cmatch(date, tmztype);
169 }
170 
171 /*
172  * Match the given string (cp) against the given template (tp).
173  * Return 1 if they match, 0 if they don't
174  */
175 cmatch(cp, tp)
176 	register char *cp, *tp;
177 {
178 
179 	while (*cp && *tp)
180 		switch (*tp++) {
181 		case 'a':
182 			if (!islower(*cp++))
183 				return 0;
184 			break;
185 		case 'A':
186 			if (!isupper(*cp++))
187 				return 0;
188 			break;
189 		case ' ':
190 			if (*cp++ != ' ')
191 				return 0;
192 			break;
193 		case '0':
194 			if (!isdigit(*cp++))
195 				return 0;
196 			break;
197 		case 'O':
198 			if (*cp != ' ' && !isdigit(*cp))
199 				return 0;
200 			cp++;
201 			break;
202 		case ':':
203 			if (*cp++ != ':')
204 				return 0;
205 			break;
206 		case 'N':
207 			if (*cp++ != '\n')
208 				return 0;
209 			break;
210 		}
211 	if (*cp || *tp)
212 		return 0;
213 	return (1);
214 }
215 
216 /*
217  * Collect a liberal (space, tab delimited) word into the word buffer
218  * passed.  Also, return a pointer to the next word following that,
219  * or NOSTR if none follow.
220  */
221 char *
222 nextword(wp, wbuf)
223 	register char *wp, *wbuf;
224 {
225 	register c;
226 
227 	if (wp == NOSTR) {
228 		*wbuf = 0;
229 		return (NOSTR);
230 	}
231 	while ((c = *wp++) && c != ' ' && c != '\t') {
232 		*wbuf++ = c;
233 		if (c == '"') {
234  			while ((c = *wp++) && c != '"')
235  				*wbuf++ = c;
236  			if (c == '"')
237  				*wbuf++ = c;
238 			else
239 				wp--;
240  		}
241 	}
242 	*wbuf = '\0';
243 	for (; c == ' ' || c == '\t'; c = *wp++)
244 		;
245 	if (c == 0)
246 		return (NOSTR);
247 	return (wp - 1);
248 }
249