usr.bin/strings/strings.c

   1 /*
   2  * Copyright (c) 1980, 1987, 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  * @(#) Copyright (c) 1980, 1987, 1993 The Regents of the University of California.  All rights reserved.
  34  * @(#)strings.c        8.2 (Berkeley) 1/28/94
  35  * $FreeBSD: src/usr.bin/strings/strings.c,v 1.8.2.1 2001/03/04 09:05:54 kris Exp $
  36  * $DragonFly: src/usr.bin/strings/Attic/strings.c,v 1.4 2004/12/31 03:53:25 dillon Exp $
  37  */
  38
  39 #include <sys/types.h>
  40 #include <sys/socket.h>
  41 #include <netinet/in.h>
  42 #include <arpa/inet.h>
  43
  44 #include <a.out.h>
  45 #include <ctype.h>
  46 #include <err.h>
  47 #include <fcntl.h>
  48 #include <locale.h>
  49 #include <stdio.h>
  50 #include <stdlib.h>
  51 #include <string.h>
  52 #include <unistd.h>
  53
  54 #define DEF_LEN         4               /* default minimum string length */
  55 #define ISSTR(ch)       (isalnum(ch) || ispunct(ch) || \
  56                          (isspace(ch) && (!iscntrl(ch) || ch == '\t')) || \
  57                          (isascii(ch) && isprint(ch)))
  58
  59 typedef struct exec     EXEC;           /* struct exec cast */
  60
  61 static long     foff;                   /* offset in the file */
  62 static int      hcnt,                   /* head count */
  63                 head_len,               /* length of header */
  64                 read_len;               /* length to read */
  65 static u_char   hbfr[sizeof(EXEC)];     /* buffer for struct exec */
  66
  67 static int getch(void);
  68 static void usage(void);
  69
  70 int
  71 main(int argc, char **argv)
  72 {
  73         int ch, cnt;
  74         u_char *C = NULL;
  75         EXEC *head;
  76         int exitcode, minlen;
  77         short asdata, oflg, fflg;
  78         u_char *bfr;
  79         char *p;
  80         const char *file = "stdin";
  81
  82         setlocale(LC_CTYPE, "");
  83
  84         /*
  85          * for backward compatibility, allow '-' to specify 'a' flag; no
  86          * longer documented in the man page or usage string.
  87          */
  88         asdata = exitcode = fflg = oflg = 0;
  89         minlen = -1;
  90         while ((ch = getopt(argc, argv, "-0123456789an:of")) != -1)
  91                 switch (ch) {
  92                 case '0': case '1': case '2': case '3': case '4':
  93                 case '5': case '6': case '7': case '8': case '9':
  94                         /*
  95                          * kludge: strings was originally designed to take
  96                          * a number after a dash.
  97                          */
  98                         if (minlen == -1) {
  99                                 p = argv[optind - 1];
 100                                 if (p[0] == '-' && p[1] == ch && !p[2])
 101                                         minlen = atoi(++p);
 102                                 else
 103                                         minlen = atoi(argv[optind] + 1);
 104                         }
 105                         break;
 106                 case '-':
 107                 case 'a':
 108                         asdata = 1;
 109                         break;
 110                 case 'f':
 111                         fflg = 1;
 112                         break;
 113                 case 'n':
 114                         minlen = atoi(optarg);
 115                         break;
 116                 case 'o':
 117                         oflg = 1;
 118                         break;
 119                 case '?':
 120                 default:
 121                         usage();
 122                 }
 123         argc -= optind;
 124         argv += optind;
 125
 126         if (minlen == -1)
 127                 minlen = DEF_LEN;
 128         else if (minlen < 1)
 129                 errx(1, "length less than 1");
 130
 131         if (!(bfr = malloc((u_int)minlen + 1)))
 132                 err(1, "malloc");
 133         bfr[minlen] = '\0';
 134         do {
 135                 if (*argv) {
 136                         file = *argv++;
 137                         if (!freopen(file, "r", stdin)) {
 138                                 warn("%s", file);
 139                                 exitcode = 1;
 140                                 goto nextfile;
 141                         }
 142                 }
 143                 foff = 0;
 144 #define DO_EVERYTHING()         {read_len = -1; head_len = 0; goto start;}
 145                 read_len = -1;
 146                 if (asdata)
 147                         DO_EVERYTHING()
 148                 else {
 149                         head = (EXEC *)hbfr;
 150                         if ((head_len =
 151                             read(fileno(stdin), head, sizeof(EXEC))) == -1)
 152                                 DO_EVERYTHING()
 153                         if (head_len == sizeof(EXEC) && !N_BADMAG(*head)) {
 154                                 foff = N_TXTOFF(*head);
 155                                 if (fseek(stdin, foff, SEEK_SET) == -1)
 156                                         DO_EVERYTHING()
 157                                 read_len = head->a_text + head->a_data;
 158                                 head_len = 0;
 159                         }
 160                         else
 161                                 hcnt = 0;
 162                 }
 163 start:
 164                 for (cnt = 0; (ch = getch()) != EOF;) {
 165                         if (ISSTR(ch)) {
 166                                 if (!cnt)
 167                                         C = bfr;
 168                                 *C++ = ch;
 169                                 if (++cnt < minlen)
 170                                         continue;
 171                                 if (fflg)
 172                                         printf("%s:", file);
 173                                 if (oflg)
 174                                         printf("%07ld %s",
 175                                             foff - minlen, (char *)bfr);
 176                                 else
 177                                         printf("%s", bfr);
 178                                 while ((ch = getch()) != EOF && ISSTR(ch))
 179                                         putchar((char)ch);
 180                                 putchar('\n');
 181                         }
 182                         cnt = 0;
 183                 }
 184 nextfile: ;
 185         } while (*argv);
 186         exit(exitcode);
 187 }
 188
 189 /*
 190  * getch --
 191  *      get next character from wherever
 192  */
 193 static int
 194 getch(void)
 195 {
 196         ++foff;
 197         if (head_len) {
 198                 if (hcnt < head_len)
 199                         return((int)hbfr[hcnt++]);
 200                 head_len = 0;
 201         }
 202         if (read_len == -1 || read_len-- > 0)
 203                 return(getchar());
 204         return(EOF);
 205 }
 206
 207 static void
 208 usage(void)
 209 {
 210         fprintf(stderr,
 211             "usage: strings [-afo] [-n length] [file ... ]\n");
 212         exit(1);
 213 }