1 /* $OpenBSD: from.c,v 1.25 2017/05/31 19:41:30 millert Exp $ */ 2 /* $NetBSD: from.c,v 1.6 1995/09/01 01:39:10 jtc Exp $ */ 3 4 /* 5 * Copyright (c) 1980, 1988, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #include <sys/types.h> 34 #include <ctype.h> 35 #include <pwd.h> 36 #include <stdio.h> 37 #include <stdlib.h> 38 #include <unistd.h> 39 #include <paths.h> 40 #include <string.h> 41 #include <err.h> 42 #include <errno.h> 43 44 int match(char *, char *); 45 char *mail_spool(char *file, const char *user); 46 47 int 48 main(int argc, char *argv[]) 49 { 50 int ch, newline, fflag = 0; 51 char *file, *line, *sender, *p; 52 size_t linesize = 0; 53 ssize_t linelen; 54 FILE *fp; 55 56 file = line = sender = NULL; 57 while ((ch = getopt(argc, argv, "f:s:")) != -1) { 58 switch(ch) { 59 case 'f': 60 fflag = 1; 61 file = optarg; 62 break; 63 case 's': 64 sender = optarg; 65 for (p = sender; *p; ++p) 66 if (isupper((unsigned char)*p)) 67 *p = tolower((unsigned char)*p); 68 break; 69 default: 70 fprintf(stderr, 71 "usage: from [-f file] [-s sender] [user]\n"); 72 exit(EXIT_FAILURE); 73 } 74 } 75 argv += optind; 76 77 if (pledge("stdio rpath getpw", NULL) == -1) 78 err(1, "pledge"); 79 80 file = mail_spool(file, *argv); 81 if ((fp = fopen(file, "r")) == NULL) { 82 if (!fflag && errno == ENOENT) 83 exit(EXIT_SUCCESS); 84 err(1, "%s", file); 85 } 86 87 if (pledge("stdio", NULL) == -1) 88 err(1, "pledge"); 89 90 for (newline = 1; (linelen = getline(&line, &linesize, fp)) != -1;) { 91 if (*line == '\n') { 92 newline = 1; 93 continue; 94 } 95 if (newline && !strncmp(line, "From ", 5) && 96 (!sender || match(line + 5, sender))) 97 printf("%s", line); 98 newline = 0; 99 } 100 free(line); 101 if (ferror(fp)) 102 err(EXIT_FAILURE, "getline"); 103 fclose(fp); 104 exit(EXIT_SUCCESS); 105 } 106 107 char * 108 mail_spool(char *file, const char *user) 109 { 110 struct passwd *pwd; 111 112 /* 113 * We find the mailbox by: 114 * 1 -f flag 115 * 2 _PATH_MAILDIR/user (from argv) 116 * 2 MAIL environment variable 117 * 3 _PATH_MAILDIR/user (from environment or passwd db) 118 */ 119 if (file == NULL) { 120 if (user == NULL) { 121 if ((file = getenv("MAIL")) == NULL) { 122 if ((user = getenv("LOGNAME")) == NULL && 123 (user = getenv("USER")) == NULL) { 124 if (!(pwd = getpwuid(getuid()))) 125 errx(1, "no password file " 126 "entry for you"); 127 user = pwd->pw_name; 128 } 129 } 130 } 131 if (file == NULL) { 132 if (asprintf(&file, "%s/%s", _PATH_MAILDIR, user) == -1) 133 err(1, NULL); 134 } 135 } 136 return(file); 137 } 138 139 int 140 match(char *line, char *sender) 141 { 142 char ch, pch, first, *p, *t; 143 144 for (first = *sender++;;) { 145 if (isspace((unsigned char)(ch = *line))) 146 return(0); 147 ++line; 148 if (isupper((unsigned char)ch)) 149 ch = tolower((unsigned char)ch); 150 if (ch != first) 151 continue; 152 for (p = sender, t = line;;) { 153 if (!(pch = *p++)) 154 return(1); 155 if (isupper((unsigned char)(ch = *t++))) 156 ch = tolower((unsigned char)ch); 157 if (ch != pch) 158 break; 159 } 160 } 161 /* NOTREACHED */ 162 } 163