usr.bin/from/from.c

   1 /*      $NetBSD: from.c,v 1.17 2008/07/21 14:19:22 lukem Exp $  */
   2
   3 /*
   4  * Copyright (c) 1980, 1988, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #ifndef lint
  34 __COPYRIGHT("@(#) Copyright (c) 1980, 1988, 1993\
  35  The Regents of the University of California.  All rights reserved.");
  36 #endif /* not lint */
  37
  38 #ifndef lint
  39 #if 0
  40 static char sccsid[] = "@(#)from.c      8.1 (Berkeley) 6/6/93";
  41 #endif
  42 __RCSID("$NetBSD: from.c,v 1.17 2008/07/21 14:19:22 lukem Exp $");
  43 #endif /* not lint */
  44
  45 #include <sys/types.h>
  46 #include <ctype.h>
  47 #include <err.h>
  48 #include <paths.h>
  49 #include <pwd.h>
  50 #include <stdio.h>
  51 #include <stdlib.h>
  52 #include <string.h>
  53 #include <unistd.h>
  54
  55 int     main (int, char **);
  56 int     match (const char *, const char *);
  57
  58 int
  59 main(int argc, char **argv)
  60 {
  61         struct passwd *pwd;
  62         int ch, newline;
  63         char *file, *sender, *p;
  64 #if MAXPATHLEN > BUFSIZ
  65         char buf[MAXPATHLEN];
  66 #else
  67         char buf[BUFSIZ];
  68 #endif
  69
  70         file = sender = NULL;
  71         while ((ch = getopt(argc, argv, "f:s:")) != -1)
  72                 switch((char)ch) {
  73                 case 'f':
  74                         file = optarg;
  75                         break;
  76                 case 's':
  77                         sender = optarg;
  78                         for (p = sender; *p; ++p)
  79                                 *p = tolower((unsigned char)*p);
  80                         break;
  81                 default:
  82                         fprintf(stderr, "usage: from [-f file] [-s sender] [user]\n");
  83                         exit(1);
  84                 }
  85         argv += optind;
  86
  87         /*
  88          * We find the mailbox by:
  89          *      1 -f flag
  90          *      2 user
  91          *      2 MAIL environment variable
  92          *      3 _PATH_MAILDIR/file
  93          */
  94         if (!file) {
  95                 if (!(file = *argv)) {
  96                         if (!(file = getenv("MAIL"))) {
  97                                 if (!(pwd = getpwuid(getuid())))
  98                                         errx(1, "no password file entry for you");
  99                                 if ((file = getenv("LOGNAME")) != NULL ||
 100                                     (file = getenv("USER")) != NULL) {
 101                                         (void)snprintf(buf, sizeof(buf),
 102                                             "%s/%s", _PATH_MAILDIR, file);
 103                                         file = buf;
 104                                 } else
 105                                         (void)snprintf(file = buf, sizeof(buf),
 106                                             "%s/%s",
 107                                             _PATH_MAILDIR, pwd->pw_name);
 108                         }
 109                 } else {
 110                         (void)snprintf(buf, sizeof(buf), "%s/%s",
 111                                 _PATH_MAILDIR, file);
 112                         file = buf;
 113                 }
 114         }
 115         if (!freopen(file, "r", stdin))
 116                 err(1, "can't read %s", file);
 117
 118         for (newline = 1; fgets(buf, sizeof(buf), stdin);) {
 119                 if (*buf == '\n') {
 120                         newline = 1;
 121                         continue;
 122                 }
 123                 if (newline && !strncmp(buf, "From ", 5) &&
 124                     (!sender || match(buf + 5, sender)))
 125                         printf("%s", buf);
 126                 newline = 0;
 127         }
 128         exit(0);
 129 }
 130
 131 int
 132 match(const char *line, const char *sender)
 133 {
 134         char ch, pch, first;
 135         const char *p, *t;
 136
 137         for (first = *sender++;;) {
 138                 if (isspace((unsigned char)(ch = *line)))
 139                         return(0);
 140                 ++line;
 141                 ch = tolower((unsigned char)ch);
 142                 if (ch != first)
 143                         continue;
 144                 for (p = sender, t = line;;) {
 145                         if (!(pch = *p++))
 146                                 return(1);
 147                         ch = tolower((unsigned char)*t++);
 148                         if (ch != pch)
 149                                 break;
 150                 }
 151         }
 152         /* NOTREACHED */
 153 }