usr.bin/from/from.c

   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. 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  * @(#) Copyright (c) 1980, 1988, 1993 The Regents of the University of California.  All rights reserved.
  30  * @(#)from.c   8.1 (Berkeley) 6/6/93
  31  * $FreeBSD: src/usr.bin/from/from.c,v 1.8.2.1 2000/10/06 08:19:19 ru Exp $
  32  * $DragonFly: src/usr.bin/from/from.c,v 1.5 2005/04/22 15:36:39 liamfoy Exp $
  33  */
  34
  35 #include <sys/types.h>
  36
  37 #include <ctype.h>
  38 #include <err.h>
  39 #include <pwd.h>
  40 #include <stdio.h>
  41 #include <stdlib.h>
  42 #include <paths.h>
  43 #include <string.h>
  44 #include <unistd.h>
  45
  46 static int      match(char *, char *);
  47 static void     usage(void);
  48
  49 int
  50 main(int argc, char **argv)
  51 {
  52         struct passwd *pwd;
  53         int ch, count, newline;
  54         const char *file;
  55         char *sender, *p;
  56 #if MAXPATHLEN > BUFSIZ
  57         char buf[MAXPATHLEN];
  58 #else
  59         char buf[BUFSIZ];
  60 #endif
  61
  62         file = sender = NULL;
  63         count = -1;
  64         while ((ch = getopt(argc, argv, "cf:s:")) != -1)
  65                 switch (ch) {
  66                 case 'c':
  67                         count = 0;
  68                         break;
  69                 case 'f':
  70                         file = optarg;
  71                         break;
  72                 case 's':
  73                         sender = optarg;
  74                         for (p = sender; *p; ++p)
  75                                 *p = tolower(*p);
  76                         break;
  77                 case '?':
  78                 default:
  79                         usage();
  80                 }
  81         argv += optind;
  82
  83         if (file == NULL) {
  84                 if (*argv) {
  85                         snprintf(buf, sizeof(buf), "%s/%s", _PATH_MAILDIR, *argv);
  86                         file  = buf;
  87                 } else {
  88                         if ((file = getenv("MAIL")) == NULL) {
  89                                 if (!(pwd = getpwuid(getuid())))
  90                                         errx(1, "no password file entry for you");
  91                                 file = pwd->pw_name;
  92                                 snprintf(buf, sizeof(buf),
  93                                     "%s/%s", _PATH_MAILDIR, file);
  94                                 file = buf;
  95                         }
  96                 }
  97         }
  98
  99         /* read from stdin */
 100         if (strcmp(file, "-") == 0) {
 101         }
 102         else if (freopen(file, "r", stdin) == NULL) {
 103                 err(1, "can't read %s", file);
 104         }
 105         for (newline = 1; fgets(buf, sizeof(buf), stdin);) {
 106                 if (*buf == '\n') {
 107                         newline = 1;
 108                         continue;
 109                 }
 110                 if (newline && !strncmp(buf, "From ", 5) &&
 111                     (!sender || match(buf + 5, sender))) {
 112                         if (count != -1)
 113                                 count++;
 114                         else
 115                                 printf("%s", buf);
 116                 }
 117                 newline = 0;
 118         }
 119         if (count != -1)
 120                 printf("There %s %d message%s in your incoming mailbox.\n",
 121                     count == 1 ? "is" : "are", count, count == 1 ? "" : "s");
 122         exit(0);
 123 }
 124
 125 static void
 126 usage(void)
 127 {
 128         fprintf(stderr, "usage: from [-c] [-f file] [-s sender] [user]\n");
 129         exit(1);
 130 }
 131
 132 static int
 133 match(char *line, char *sender)
 134 {
 135         char ch, pch, first, *p, *t;
 136
 137         for (first = *sender++;;) {
 138                 if (isspace(ch = *line))
 139                         return(0);
 140                 ++line;
 141                 ch = tolower(ch);
 142                 if (ch != first)
 143                         continue;
 144                 for (p = sender, t = line;;) {
 145                         if (!(pch = *p++))
 146                                 return(1);
 147                         ch = tolower(*t++);
 148                         if (ch != pch)
 149                                 break;
 150                 }
 151         }
 152         /* NOTREACHED */
 153 }