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
54static int 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				*p = tolower(*p);
85			break;
86		case '?':
87		default:
88			usage();
89		}
90	argc -= optind;
91	argv += optind;
92
93	if (file == NULL) {
94		if (argc) {
95			(void)snprintf(buf, sizeof(buf), "%s/%s", _PATH_MAILDIR, *argv);
96			file  = buf;
97		} else {
98			if (!(file = getenv("MAIL"))) {
99				if (!(pwd = getpwuid(getuid())))
100					errx(1, "no password file entry for you");
101				file = pwd->pw_name;
102				(void)snprintf(buf, sizeof(buf),
103				    "%s/%s", _PATH_MAILDIR, file);
104				file = buf;
105			}
106		}
107	}
108
109	/* read from stdin */
110	if (strcmp(file, "-") == 0) {
111		mbox = stdin;
112	}
113	else if ((mbox = fopen(file, "r")) == NULL) {
114		errx(1, "can't read %s", file);
115	}
116	for (newline = 1; fgets(buf, sizeof(buf), mbox);) {
117		if (*buf == '\n') {
118			newline = 1;
119			continue;
120		}
121		if (newline && !strncmp(buf, "From ", 5) &&
122		    (!sender || match(buf + 5, sender))) {
123			if (count != -1)
124				count++;
125			else
126				printf("%s", buf);
127		}
128		newline = 0;
129	}
130	if (count != -1)
131		printf("There %s %d message%s in your incoming mailbox.\n",
132		    count == 1 ? "is" : "are", count, count == 1 ? "" : "s");
133	fclose(mbox);
134	exit(0);
135}
136
137static void
138usage(void)
139{
140	fprintf(stderr, "usage: from [-c] [-f file] [-s sender] [user]\n");
141	exit(1);
142}
143
144static int
145match(const char *line, const char *sender)
146{
147	char ch, pch, first;
148	const char *p, *t;
149
150	for (first = *sender++;;) {
151		if (isspace(ch = *line))
152			return(0);
153		++line;
154		ch = tolower(ch);
155		if (ch != first)
156			continue;
157		for (p = sender, t = line;;) {
158			if (!(pch = *p++))
159				return(1);
160			ch = tolower(*t);
161			t++;
162			if (ch != pch)
163				break;
164		}
165	}
166	/* NOTREACHED */
167}
168