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 * 4. Neither the name of the University nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#ifndef lint
31static const char copyright[] =
32"@(#) Copyright (c) 1980, 1988, 1993\n\
33	The Regents of the University of California.  All rights reserved.\n";
34#endif /* not lint */
35
36#ifndef lint
37#if 0
38static char sccsid[] = "@(#)from.c	8.1 (Berkeley) 6/6/93";
39#endif
40#endif /* not lint */
41#include <sys/cdefs.h>
42__FBSDID("$FreeBSD$");
43
44#include <sys/types.h>
45#include <ctype.h>
46#include <err.h>
47#include <pwd.h>
48#include <stdio.h>
49#include <stdlib.h>
50#include <paths.h>
51#include <string.h>
52#include <unistd.h>
53
54int match(const char *, const char *);
55static void usage(void);
56
57int
58main(int argc, char **argv)
59{
60	FILE *mbox;
61	struct passwd *pwd;
62	int ch, count, newline;
63	const char *file;
64	char *sender, *p;
65#if MAXPATHLEN > BUFSIZ
66	char buf[MAXPATHLEN];
67#else
68	char buf[BUFSIZ];
69#endif
70
71	file = sender = NULL;
72	count = -1;
73	while ((ch = getopt(argc, argv, "cf:s:")) != -1)
74		switch (ch) {
75		case 'c':
76			count = 0;
77			break;
78		case 'f':
79			file = optarg;
80			break;
81		case 's':
82			sender = optarg;
83			for (p = sender; *p; ++p)
84				if (isupper(*p))
85					*p = tolower(*p);
86			break;
87		case '?':
88		default:
89			usage();
90		}
91	argc -= optind;
92	argv += optind;
93
94	if (file == NULL) {
95		if (argc) {
96			(void)snprintf(buf, sizeof(buf), "%s/%s", _PATH_MAILDIR, *argv);
97			file  = buf;
98		} else {
99			if (!(file = getenv("MAIL"))) {
100				if (!(pwd = getpwuid(getuid())))
101					errx(1, "no password file entry for you");
102				file = pwd->pw_name;
103				(void)snprintf(buf, sizeof(buf),
104				    "%s/%s", _PATH_MAILDIR, file);
105				file = buf;
106			}
107		}
108	}
109
110	/* read from stdin */
111	if (strcmp(file, "-") == 0) {
112		mbox = stdin;
113	}
114	else if ((mbox = fopen(file, "r")) == NULL) {
115		errx(1, "can't read %s", file);
116	}
117	for (newline = 1; fgets(buf, sizeof(buf), mbox);) {
118		if (*buf == '\n') {
119			newline = 1;
120			continue;
121		}
122		if (newline && !strncmp(buf, "From ", 5) &&
123		    (!sender || match(buf + 5, sender))) {
124			if (count != -1)
125				count++;
126			else
127				printf("%s", buf);
128		}
129		newline = 0;
130	}
131	if (count != -1)
132		printf("There %s %d message%s in your incoming mailbox.\n",
133		    count == 1 ? "is" : "are", count, count == 1 ? "" : "s");
134	fclose(mbox);
135	exit(0);
136}
137
138static void
139usage(void)
140{
141	fprintf(stderr, "usage: from [-c] [-f file] [-s sender] [user]\n");
142	exit(1);
143}
144
145int
146match(const char *line, const char *sender)
147{
148	char ch, pch, first;
149	const char *p, *t;
150
151	for (first = *sender++;;) {
152		if (isspace(ch = *line))
153			return(0);
154		++line;
155		if (isupper(ch))
156			ch = tolower(ch);
157		if (ch != first)
158			continue;
159		for (p = sender, t = line;;) {
160			if (!(pch = *p++))
161				return(1);
162			if (isupper(ch = *t++))
163				ch = tolower(ch);
164			if (ch != pch)
165				break;
166		}
167	}
168	/* NOTREACHED */
169}
170