from.c revision 102944 
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
35static const char copyright[] =
36"@(#) Copyright (c) 1980, 1988, 1993\n\
37	The Regents of the University of California.  All rights reserved.\n";
38#endif /* not lint */
39
40#ifndef lint
41#if 0
42static char sccsid[] = "@(#)from.c	8.1 (Berkeley) 6/6/93";
43#endif
44#endif /* not lint */
45#include <sys/cdefs.h>
46__FBSDID("$FreeBSD: head/usr.bin/from/from.c 102944 2002-09-04 23:29:10Z dwmalone $");
47
48#include <sys/types.h>
49#include <ctype.h>
50#include <err.h>
51#include <pwd.h>
52#include <stdio.h>
53#include <stdlib.h>
54#include <paths.h>
55#include <string.h>
56#include <unistd.h>
57
58int match(const char *, const char *);
59static void usage(void);
60
61int
62main(int argc, char **argv)
63{
64	FILE *mbox;
65	struct passwd *pwd;
66	int ch, count, newline;
67	const char *file;
68	char *sender, *p;
69#if MAXPATHLEN > BUFSIZ
70	char buf[MAXPATHLEN];
71#else
72	char buf[BUFSIZ];
73#endif
74
75	file = sender = NULL;
76	count = -1;
77	while ((ch = getopt(argc, argv, "cf:s:")) != -1)
78		switch (ch) {
79		case 'c':
80			count = 0;
81			break;
82		case 'f':
83			file = optarg;
84			break;
85		case 's':
86			sender = optarg;
87			for (p = sender; *p; ++p)
88				if (isupper(*p))
89					*p = tolower(*p);
90			break;
91		case '?':
92		default:
93			usage();
94		}
95	argc -= optind;
96	argv += optind;
97
98	if (file == NULL) {
99		if (argc) {
100			(void)snprintf(buf, sizeof(buf), "%s/%s", _PATH_MAILDIR, *argv);
101			file  = buf;
102		} else {
103			if (!(file = getenv("MAIL"))) {
104				if (!(pwd = getpwuid(getuid())))
105					errx(1, "no password file entry for you");
106				file = pwd->pw_name;
107				(void)snprintf(buf, sizeof(buf),
108				    "%s/%s", _PATH_MAILDIR, file);
109				file = buf;
110			}
111		}
112	}
113
114	/* read from stdin */
115	if (strcmp(file, "-") == 0) {
116		mbox = stdin;
117	}
118	else if ((mbox = fopen(file, "r")) == NULL) {
119		errx(1, "can't read %s", file);
120	}
121	for (newline = 1; fgets(buf, sizeof(buf), mbox);) {
122		if (*buf == '\n') {
123			newline = 1;
124			continue;
125		}
126		if (newline && !strncmp(buf, "From ", 5) &&
127		    (!sender || match(buf + 5, sender))) {
128			if (count != -1)
129				count++;
130			else
131				printf("%s", buf);
132		}
133		newline = 0;
134	}
135	if (count != -1)
136		printf("There %s %d message%s in your incoming mailbox.\n",
137		    count == 1 ? "is" : "are", count, count == 1 ? "" : "s");
138	fclose(mbox);
139	exit(0);
140}
141
142static void
143usage(void)
144{
145	fprintf(stderr, "usage: from [-c] [-f file] [-s sender] [user]\n");
146	exit(1);
147}
148
149int
150match(const char *line, const char *sender)
151{
152	char ch, pch, first;
153	const char *p, *t;
154
155	for (first = *sender++;;) {
156		if (isspace(ch = *line))
157			return(0);
158		++line;
159		if (isupper(ch))
160			ch = tolower(ch);
161		if (ch != first)
162			continue;
163		for (p = sender, t = line;;) {
164			if (!(pch = *p++))
165				return(1);
166			if (isupper(ch = *t++))
167				ch = tolower(ch);
168			if (ch != pch)
169				break;
170		}
171	}
172	/* NOTREACHED */
173}
174