1/*
2 * Copyright (c) 1980, 1988, 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__attribute__((__used__))
36static const char copyright[] =
37"@(#) Copyright (c) 1980, 1988, 1993\n\
38	The Regents of the University of California.  All rights reserved.\n";
39#endif /* not lint */
40
41#ifndef lint
42#if 0
43static char sccsid[] = "@(#)from.c	8.1 (Berkeley) 6/6/93";
44#endif
45#endif /* not lint */
46#include <sys/cdefs.h>
47__RCSID("$FreeBSD: src/usr.bin/from/from.c,v 1.14 2002/09/04 23:29:00 dwmalone Exp $");
48
49#include <sys/types.h>
50#include <ctype.h>
51#include <err.h>
52#include <pwd.h>
53#include <stdio.h>
54#include <stdlib.h>
55#include <paths.h>
56#include <string.h>
57#include <unistd.h>
58
59int match(const char *, const char *);
60static void usage(void);
61
62int
63main(int argc, char **argv)
64{
65	FILE *mbox;
66	struct passwd *pwd;
67	int ch, count, newline;
68	const char *file;
69	char *sender, *p;
70#if MAXPATHLEN > BUFSIZ
71	char buf[MAXPATHLEN];
72#else
73	char buf[BUFSIZ];
74#endif
75
76	file = sender = NULL;
77	count = -1;
78	while ((ch = getopt(argc, argv, "cf:s:")) != -1)
79		switch (ch) {
80		case 'c':
81			count = 0;
82			break;
83		case 'f':
84			file = optarg;
85			break;
86		case 's':
87			sender = optarg;
88			for (p = sender; *p; ++p)
89				if (isupper(*p))
90					*p = tolower(*p);
91			break;
92		case '?':
93		default:
94			usage();
95		}
96	argc -= optind;
97	argv += optind;
98
99	if (file == NULL) {
100		if (argc) {
101			(void)snprintf(buf, sizeof(buf), "%s/%s", _PATH_MAILDIR, *argv);
102			file  = buf;
103		} else {
104			if (!(file = getenv("MAIL"))) {
105				if (!(pwd = getpwuid(getuid())))
106					errx(1, "no password file entry for you");
107				file = pwd->pw_name;
108				(void)snprintf(buf, sizeof(buf),
109				    "%s/%s", _PATH_MAILDIR, file);
110				file = buf;
111			}
112		}
113	}
114
115	/* read from stdin */
116	if (strcmp(file, "-") == 0) {
117		mbox = stdin;
118	}
119	else if ((mbox = fopen(file, "r")) == NULL) {
120		errx(1, "can't read %s", file);
121	}
122	for (newline = 1; fgets(buf, sizeof(buf), mbox);) {
123		if (*buf == '\n') {
124			newline = 1;
125			continue;
126		}
127		if (newline && !strncmp(buf, "From ", 5) &&
128		    (!sender || match(buf + 5, sender))) {
129			if (count != -1)
130				count++;
131			else
132				printf("%s", buf);
133		}
134		newline = 0;
135	}
136	if (count != -1)
137		printf("There %s %d message%s in your incoming mailbox.\n",
138		    count == 1 ? "is" : "are", count, count == 1 ? "" : "s");
139	fclose(mbox);
140	exit(0);
141}
142
143static void
144usage(void)
145{
146	fprintf(stderr, "usage: from [-c] [-f file] [-s sender] [user]\n");
147	exit(1);
148}
149
150int
151match(const char *line, const char *sender)
152{
153	char ch, pch, first;
154	const char *p, *t;
155
156	for (first = *sender++;;) {
157		if (isspace(ch = *line))
158			return(0);
159		++line;
160		if (isupper(ch))
161			ch = tolower(ch);
162		if (ch != first)
163			continue;
164		for (p = sender, t = line;;) {
165			if (!(pch = *p++))
166				return(1);
167			if (isupper(ch = *t++))
168				ch = tolower(ch);
169			if (ch != pch)
170				break;
171		}
172	}
173	/* NOTREACHED */
174}
175