xref: /illumos-gate/usr/src/ucbcmd/from/from.c (revision 4283d10e18fc3904736c7c067fb29de9bb67d25d)
1 /*
2  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 /*
7  * Copyright (c) 1980 Regents of the University of California.
8  * All rights reserved.  The Berkeley software License Agreement
9  * specifies the terms and conditions for redistribution.
10  */
11 
12 #include <stdio.h>
13 #include <sys/types.h>
14 #include <unistd.h>
15 #include <stdlib.h>
16 #include <ctype.h>
17 #include <pwd.h>
18 #include <sys/param.h>
19 #include <string.h>
20 
21 static int match(char *, char *);
22 
23 int
24 main(int argc, char **argv)
25 {
26 	char lbuf[BUFSIZ];
27 	char lbuf2[BUFSIZ];
28 	struct passwd *pp;
29 	int stashed = 0;
30 	char *name;
31 	char *sender = NULL;
32 	char mailbox[MAXPATHLEN];
33 	char *tmp_mailbox;
34 	extern char *optarg;
35 	extern int optind;
36 	extern int opterr;
37 	int c;
38 	int errflg = 0;
39 
40 	opterr = 0;
41 	while ((c = getopt(argc, argv, "s:")) != EOF)
42 		switch (c) {
43 		case 's':
44 			sender = optarg;
45 			for (name = sender; *name; name++)
46 				if (isupper(*name))
47 					*name = tolower(*name);
48 			break;
49 		case '?':
50 			errflg++;
51 			break;
52 		}
53 	if (errflg) {
54 		(void) fprintf(stderr,
55 			    "Usage: from [-s sender] [user]\n");
56 		exit(1);
57 	}
58 
59 	if (optind < argc) {
60 		(void) sprintf(mailbox, "/var/mail/%s", argv[optind]);
61 	} else {
62 		if (tmp_mailbox = getenv("MAIL")) {
63 			(void) strcpy(mailbox, tmp_mailbox);
64 		} else {
65 			name = getlogin();
66 			if (name == NULL || strlen(name) == 0) {
67 				pp = getpwuid(getuid());
68 				if (pp == NULL) {
69 					(void) fprintf(stderr,
70 					    "Who are you?\n");
71 					exit(1);
72 				}
73 				name = pp->pw_name;
74 			}
75 			(void) sprintf(mailbox, "/var/mail/%s", name);
76 		}
77 	}
78 	if (freopen(mailbox, "r", stdin) == NULL) {
79 		(void) fprintf(stderr, "Can't open %s\n", mailbox);
80 		exit(0);
81 	}
82 	while (fgets(lbuf, sizeof (lbuf), stdin) != NULL)
83 		if (lbuf[0] == '\n' && stashed) {
84 			stashed = 0;
85 			(void) printf("%s", lbuf2);
86 		} else if (strncmp(lbuf, "From ", 5) == 0 &&
87 		    (sender == NULL || match(&lbuf[4], sender))) {
88 			(void) strcpy(lbuf2, lbuf);
89 			stashed = 1;
90 		}
91 	if (stashed)
92 		(void) printf("%s", lbuf2);
93 	return (0);
94 }
95 
96 static int
97 match(char *line, char *str)
98 {
99 	char ch;
100 
101 	while (*line == ' ' || *line == '\t')
102 		++line;
103 	if (*line == '\n')
104 		return (0);
105 	while (*str && *line != ' ' && *line != '\t' && *line != '\n') {
106 		ch = isupper(*line) ? tolower(*line) : *line;
107 		if (ch != *str++)
108 			return (0);
109 		line++;
110 	}
111 	return (*str == '\0');
112 }
113