xref: /freebsd/usr.bin/from/from.c (revision c4f6a2a9e1b1879b618c436ab4f56ff75c73a0f5)
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 static 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
42 static char sccsid[] = "@(#)from.c	8.1 (Berkeley) 6/6/93";
43 #endif
44 #endif /* not lint */
45 #include <sys/cdefs.h>
46 __FBSDID("$FreeBSD$");
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 
58 int match(char *, char *);
59 static void usage(void);
60 
61 int
62 main(int argc, char **argv)
63 {
64 	FILE *mbox;
65 	struct passwd *pwd;
66 	int ch, count, newline;
67 	char *file, *sender, *p;
68 #if MAXPATHLEN > BUFSIZ
69 	char buf[MAXPATHLEN];
70 #else
71 	char buf[BUFSIZ];
72 #endif
73 
74 	file = sender = NULL;
75 	count = -1;
76 	while ((ch = getopt(argc, argv, "cf:s:")) != -1)
77 		switch (ch) {
78 		case 'c':
79 			count = 0;
80 			break;
81 		case 'f':
82 			file = optarg;
83 			break;
84 		case 's':
85 			sender = optarg;
86 			for (p = sender; *p; ++p)
87 				if (isupper(*p))
88 					*p = tolower(*p);
89 			break;
90 		case '?':
91 		default:
92 			usage();
93 		}
94 	argc -= optind;
95 	argv += optind;
96 
97 	if (file == NULL) {
98 		if (argc) {
99 			(void)snprintf(buf, sizeof(buf), "%s/%s", _PATH_MAILDIR, *argv);
100 			file  = buf;
101 		} else {
102 			if (!(file = getenv("MAIL"))) {
103 				if (!(pwd = getpwuid(getuid())))
104 					errx(1, "no password file entry for you");
105 				file = pwd->pw_name;
106 				(void)snprintf(buf, sizeof(buf),
107 				    "%s/%s", _PATH_MAILDIR, file);
108 				file = buf;
109 			}
110 		}
111 	}
112 
113 	/* read from stdin */
114 	if (strcmp(file, "-") == 0) {
115 		mbox = stdin;
116 	}
117 	else if ((mbox = fopen(file, "r")) == NULL) {
118 		errx(1, "can't read %s", file);
119 	}
120 	for (newline = 1; fgets(buf, sizeof(buf), mbox);) {
121 		if (*buf == '\n') {
122 			newline = 1;
123 			continue;
124 		}
125 		if (newline && !strncmp(buf, "From ", 5) &&
126 		    (!sender || match(buf + 5, sender))) {
127 			if (count != -1)
128 				count++;
129 			else
130 				printf("%s", buf);
131 		}
132 		newline = 0;
133 	}
134 	if (count != -1)
135 		printf("There %s %d message%s in your incoming mailbox.\n",
136 		    count == 1 ? "is" : "are", count, count == 1 ? "" : "s");
137 	fclose(mbox);
138 	exit(0);
139 }
140 
141 static void
142 usage(void)
143 {
144 	fprintf(stderr, "usage: from [-c] [-f file] [-s sender] [user]\n");
145 	exit(1);
146 }
147 
148 int
149 match(char *line, char *sender)
150 {
151 	char ch, pch, first, *p, *t;
152 
153 	for (first = *sender++;;) {
154 		if (isspace(ch = *line))
155 			return(0);
156 		++line;
157 		if (isupper(ch))
158 			ch = tolower(ch);
159 		if (ch != first)
160 			continue;
161 		for (p = sender, t = line;;) {
162 			if (!(pch = *p++))
163 				return(1);
164 			if (isupper(ch = *t++))
165 				ch = tolower(ch);
166 			if (ch != pch)
167 				break;
168 		}
169 	}
170 	/* NOTREACHED */
171 }
172