binutils/strings.c

   1 /* strings -- print the strings of printable characters in files
   2    Copyright 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
   3    2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3, or (at your option)
   8    any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software
  17    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA
  18    02110-1301, USA.  */
  19 \f
  20 /* Usage: strings [options] file...
  21
  22    Options:
  23    --all
  24    -a
  25    -            Do not scan only the initialized data section of object files.
  26
  27    --print-file-name
  28    -f           Print the name of the file before each string.
  29
  30    --bytes=min-len
  31    -n min-len
  32    -min-len     Print graphic char sequences, MIN-LEN or more bytes long,
  33                 that are followed by a NUL or a newline.  Default is 4.
  34
  35    --radix={o,x,d}
  36    -t {o,x,d}   Print the offset within the file before each string,
  37                 in octal/hex/decimal.
  38
  39    -o           Like -to.  (Some other implementations have -o like -to,
  40                 others like -td.  We chose one arbitrarily.)
  41
  42    --encoding={s,S,b,l,B,L}
  43    -e {s,S,b,l,B,L}
  44                 Select character encoding: 7-bit-character, 8-bit-character,
  45                 bigendian 16-bit, littleendian 16-bit, bigendian 32-bit,
  46                 littleendian 32-bit.
  47
  48    --target=BFDNAME
  49    -T {bfdname}
  50                 Specify a non-default object file format.
  51
  52    --help
  53    -h           Print the usage message on the standard output.
  54
  55    --version
  56    -v           Print the program version number.
  57
  58    Written by Richard Stallman <rms@gnu.ai.mit.edu>
  59    and David MacKenzie <djm@gnu.ai.mit.edu>.  */
  60
  61 #include "sysdep.h"
  62 #include "bfd.h"
  63 #include "getopt.h"
  64 #include "libiberty.h"
  65 #include "safe-ctype.h"
  66 #include <sys/stat.h>
  67 #include "bucomm.h"
  68
  69 /* Some platforms need to put stdin into binary mode, to read
  70     binary files.  */
  71 #ifdef HAVE_SETMODE
  72 #ifndef O_BINARY
  73 #ifdef _O_BINARY
  74 #define O_BINARY _O_BINARY
  75 #define setmode _setmode
  76 #else
  77 #define O_BINARY 0
  78 #endif
  79 #endif
  80 #if O_BINARY
  81 #include <io.h>
  82 #define SET_BINARY(f) do { if (!isatty (f)) setmode (f,O_BINARY); } while (0)
  83 #endif
  84 #endif
  85
  86 #define STRING_ISGRAPHIC(c) \
  87       (   (c) >= 0 \
  88        && (c) <= 255 \
  89        && ((c) == '\t' || ISPRINT (c) || (encoding == 'S' && (c) > 127)))
  90
  91 #ifndef errno
  92 extern int errno;
  93 #endif
  94
  95 /* The BFD section flags that identify an initialized data section.  */
  96 #define DATA_FLAGS (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS)
  97
  98 #ifdef HAVE_FOPEN64
  99 typedef off64_t file_off;
 100 #define file_open(s,m) fopen64(s, m)
 101 #else
 102 typedef off_t file_off;
 103 #define file_open(s,m) fopen(s, m)
 104 #endif
 105 #ifdef HAVE_STAT64
 106 typedef struct stat64 statbuf;
 107 #define file_stat(f,s) stat64(f, s)
 108 #else
 109 typedef struct stat statbuf;
 110 #define file_stat(f,s) stat(f, s)
 111 #endif
 112
 113 /* Radix for printing addresses (must be 8, 10 or 16).  */
 114 static int address_radix;
 115
 116 /* Minimum length of sequence of graphic chars to trigger output.  */
 117 static int string_min;
 118
 119 /* TRUE means print address within file for each string.  */
 120 static bfd_boolean print_addresses;
 121
 122 /* TRUE means print filename for each string.  */
 123 static bfd_boolean print_filenames;
 124
 125 /* TRUE means for object files scan only the data section.  */
 126 static bfd_boolean datasection_only;
 127
 128 /* TRUE if we found an initialized data section in the current file.  */
 129 static bfd_boolean got_a_section;
 130
 131 /* The BFD object file format.  */
 132 static char *target;
 133
 134 /* The character encoding format.  */
 135 static char encoding;
 136 static int encoding_bytes;
 137
 138 static struct option long_options[] =
 139 {
 140   {"all", no_argument, NULL, 'a'},
 141   {"print-file-name", no_argument, NULL, 'f'},
 142   {"bytes", required_argument, NULL, 'n'},
 143   {"radix", required_argument, NULL, 't'},
 144   {"encoding", required_argument, NULL, 'e'},
 145   {"target", required_argument, NULL, 'T'},
 146   {"help", no_argument, NULL, 'h'},
 147   {"version", no_argument, NULL, 'v'},
 148   {NULL, 0, NULL, 0}
 149 };
 150
 151 /* Records the size of a named file so that we
 152    do not repeatedly run bfd_stat() on it.  */
 153
 154 typedef struct
 155 {
 156   const char *  filename;
 157   bfd_size_type filesize;
 158 } filename_and_size_t;
 159
 160 static void strings_a_section (bfd *, asection *, void *);
 161 static bfd_boolean strings_object_file (const char *);
 162 static bfd_boolean strings_file (char *file);
 163 static int integer_arg (char *s);
 164 static void print_strings (const char *, FILE *, file_off, int, int, char *);
 165 static void usage (FILE *, int);
 166 static long get_char (FILE *, file_off *, int *, char **);
 167 \f
 168 int main (int, char **);
 169
 170 int
 171 main (int argc, char **argv)
 172 {
 173   int optc;
 174   int exit_status = 0;
 175   bfd_boolean files_given = FALSE;
 176
 177 #if defined (HAVE_SETLOCALE)
 178   setlocale (LC_ALL, "");
 179 #endif
 180   bindtextdomain (PACKAGE, LOCALEDIR);
 181   textdomain (PACKAGE);
 182
 183   program_name = argv[0];
 184   xmalloc_set_program_name (program_name);
 185
 186   expandargv (&argc, &argv);
 187
 188   string_min = -1;
 189   print_addresses = FALSE;
 190   print_filenames = FALSE;
 191   datasection_only = TRUE;
 192   target = NULL;
 193   encoding = 's';
 194
 195   while ((optc = getopt_long (argc, argv, "afhHn:ot:e:T:Vv0123456789",
 196                               long_options, (int *) 0)) != EOF)
 197     {
 198       switch (optc)
 199         {
 200         case 'a':
 201           datasection_only = FALSE;
 202           break;
 203
 204         case 'f':
 205           print_filenames = TRUE;
 206           break;
 207
 208         case 'H':
 209         case 'h':
 210           usage (stdout, 0);
 211
 212         case 'n':
 213           string_min = integer_arg (optarg);
 214           if (string_min < 1)
 215             fatal (_("invalid number %s"), optarg);
 216           break;
 217
 218         case 'o':
 219           print_addresses = TRUE;
 220           address_radix = 8;
 221           break;
 222
 223         case 't':
 224           print_addresses = TRUE;
 225           if (optarg[1] != '\0')
 226             usage (stderr, 1);
 227           switch (optarg[0])
 228             {
 229             case 'o':
 230               address_radix = 8;
 231               break;
 232
 233             case 'd':
 234               address_radix = 10;
 235               break;
 236
 237             case 'x':
 238               address_radix = 16;
 239               break;
 240
 241             default:
 242               usage (stderr, 1);
 243             }
 244           break;
 245
 246         case 'T':
 247           target = optarg;
 248           break;
 249
 250         case 'e':
 251           if (optarg[1] != '\0')
 252             usage (stderr, 1);
 253           encoding = optarg[0];
 254           break;
 255
 256         case 'V':
 257         case 'v':
 258           print_version ("strings");
 259           break;
 260
 261         case '?':
 262           usage (stderr, 1);
 263
 264         default:
 265           if (string_min < 0)
 266             string_min = optc - '0';
 267           else
 268             string_min = string_min * 10 + optc - '0';
 269           break;
 270         }
 271     }
 272
 273   if (string_min < 0)
 274     string_min = 4;
 275
 276   switch (encoding)
 277     {
 278     case 'S':
 279     case 's':
 280       encoding_bytes = 1;
 281       break;
 282     case 'b':
 283     case 'l':
 284       encoding_bytes = 2;
 285       break;
 286     case 'B':
 287     case 'L':
 288       encoding_bytes = 4;
 289       break;
 290     default:
 291       usage (stderr, 1);
 292     }
 293
 294   bfd_init ();
 295   set_default_bfd_target ();
 296
 297   if (optind >= argc)
 298     {
 299       datasection_only = FALSE;
 300 #ifdef SET_BINARY
 301       SET_BINARY (fileno (stdin));
 302 #endif
 303       print_strings ("{standard input}", stdin, 0, 0, 0, (char *) NULL);
 304       files_given = TRUE;
 305     }
 306   else
 307     {
 308       for (; optind < argc; ++optind)
 309         {
 310           if (strcmp (argv[optind], "-") == 0)
 311             datasection_only = FALSE;
 312           else
 313             {
 314               files_given = TRUE;
 315               exit_status |= strings_file (argv[optind]) == FALSE;
 316             }
 317         }
 318     }
 319
 320   if (!files_given)
 321     usage (stderr, 1);
 322
 323   return (exit_status);
 324 }
 325 \f
 326 /* Scan section SECT of the file ABFD, whose printable name is in
 327    ARG->filename and whose size might be in ARG->filesize.  If it
 328    contains initialized data set `got_a_section' and print the
 329    strings in it.
 330
 331    FIXME: We ought to be able to return error codes/messages for
 332    certain conditions.  */
 333
 334 static void
 335 strings_a_section (bfd *abfd, asection *sect, void *arg)
 336 {
 337   filename_and_size_t * filename_and_sizep;
 338   bfd_size_type *filesizep;
 339   bfd_size_type sectsize;
 340   void *mem;
 341
 342   if ((sect->flags & DATA_FLAGS) != DATA_FLAGS)
 343     return;
 344
 345   sectsize = bfd_get_section_size (sect);
 346
 347   if (sectsize <= 0)
 348     return;
 349
 350   /* Get the size of the file.  This might have been cached for us.  */
 351   filename_and_sizep = (filename_and_size_t *) arg;
 352   filesizep = & filename_and_sizep->filesize;
 353
 354   if (*filesizep == 0)
 355     {
 356       struct stat st;
 357
 358       if (bfd_stat (abfd, &st))
 359         return;
 360
 361       /* Cache the result so that we do not repeatedly stat this file.  */
 362       *filesizep = st.st_size;
 363     }
 364
 365   /* Compare the size of the section against the size of the file.
 366      If the section is bigger then the file must be corrupt and
 367      we should not try dumping it.  */
 368   if (sectsize >= *filesizep)
 369     return;
 370
 371   mem = xmalloc (sectsize);
 372
 373   if (bfd_get_section_contents (abfd, sect, mem, (file_ptr) 0, sectsize))
 374     {
 375       got_a_section = TRUE;
 376
 377       print_strings (filename_and_sizep->filename, NULL, sect->filepos,
 378                      0, sectsize, mem);
 379     }
 380
 381   free (mem);
 382 }
 383
 384 /* Scan all of the sections in FILE, and print the strings
 385    in the initialized data section(s).
 386
 387    Return TRUE if successful,
 388    FALSE if not (such as if FILE is not an object file).  */
 389
 390 static bfd_boolean
 391 strings_object_file (const char *file)
 392 {
 393   filename_and_size_t filename_and_size;
 394   bfd *abfd;
 395
 396   abfd = bfd_openr (file, target);
 397
 398   if (abfd == NULL)
 399     /* Treat the file as a non-object file.  */
 400     return FALSE;
 401
 402   /* This call is mainly for its side effect of reading in the sections.
 403      We follow the traditional behavior of `strings' in that we don't
 404      complain if we don't recognize a file to be an object file.  */
 405   if (!bfd_check_format (abfd, bfd_object))
 406     {
 407       bfd_close (abfd);
 408       return FALSE;
 409     }
 410
 411   got_a_section = FALSE;
 412   filename_and_size.filename = file;
 413   filename_and_size.filesize = 0;
 414   bfd_map_over_sections (abfd, strings_a_section, & filename_and_size);
 415
 416   if (!bfd_close (abfd))
 417     {
 418       bfd_nonfatal (file);
 419       return FALSE;
 420     }
 421
 422   return got_a_section;
 423 }
 424
 425 /* Print the strings in FILE.  Return TRUE if ok, FALSE if an error occurs.  */
 426
 427 static bfd_boolean
 428 strings_file (char *file)
 429 {
 430   statbuf st;
 431
 432   if (file_stat (file, &st) < 0)
 433     {
 434       if (errno == ENOENT)
 435         non_fatal (_("'%s': No such file"), file);
 436       else
 437         non_fatal (_("Warning: could not locate '%s'.  reason: %s"),
 438                    file, strerror (errno));
 439       return FALSE;
 440     }
 441
 442   /* If we weren't told to scan the whole file,
 443      try to open it as an object file and only look at
 444      initialized data sections.  If that fails, fall back to the
 445      whole file.  */
 446   if (!datasection_only || !strings_object_file (file))
 447     {
 448       FILE *stream;
 449
 450       stream = file_open (file, FOPEN_RB);
 451       if (stream == NULL)
 452         {
 453           fprintf (stderr, "%s: ", program_name);
 454           perror (file);
 455           return FALSE;
 456         }
 457
 458       print_strings (file, stream, (file_off) 0, 0, 0, (char *) 0);
 459
 460       if (fclose (stream) == EOF)
 461         {
 462           fprintf (stderr, "%s: ", program_name);
 463           perror (file);
 464           return FALSE;
 465         }
 466     }
 467
 468   return TRUE;
 469 }
 470 \f
 471 /* Read the next character, return EOF if none available.
 472    Assume that STREAM is positioned so that the next byte read
 473    is at address ADDRESS in the file.
 474
 475    If STREAM is NULL, do not read from it.
 476    The caller can supply a buffer of characters
 477    to be processed before the data in STREAM.
 478    MAGIC is the address of the buffer and
 479    MAGICCOUNT is how many characters are in it.  */
 480
 481 static long
 482 get_char (FILE *stream, file_off *address, int *magiccount, char **magic)
 483 {
 484   int c, i;
 485   long r = EOF;
 486   unsigned char buf[4];
 487
 488   for (i = 0; i < encoding_bytes; i++)
 489     {
 490       if (*magiccount)
 491         {
 492           (*magiccount)--;
 493           c = *(*magic)++;
 494         }
 495       else
 496         {
 497           if (stream == NULL)
 498             return EOF;
 499
 500           /* Only use getc_unlocked if we found a declaration for it.
 501              Otherwise, libc is not thread safe by default, and we
 502              should not use it.  */
 503
 504 #if defined(HAVE_GETC_UNLOCKED) && HAVE_DECL_GETC_UNLOCKED
 505           c = getc_unlocked (stream);
 506 #else
 507           c = getc (stream);
 508 #endif
 509           if (c == EOF)
 510             return EOF;
 511         }
 512
 513       (*address)++;
 514       buf[i] = c;
 515     }
 516
 517   switch (encoding)
 518     {
 519     case 'S':
 520     case 's':
 521       r = buf[0];
 522       break;
 523     case 'b':
 524       r = (buf[0] << 8) | buf[1];
 525       break;
 526     case 'l':
 527       r = buf[0] | (buf[1] << 8);
 528       break;
 529     case 'B':
 530       r = ((long) buf[0] << 24) | ((long) buf[1] << 16) |
 531         ((long) buf[2] << 8) | buf[3];
 532       break;
 533     case 'L':
 534       r = buf[0] | ((long) buf[1] << 8) | ((long) buf[2] << 16) |
 535         ((long) buf[3] << 24);
 536       break;
 537     }
 538
 539   if (r == EOF)
 540     return 0;
 541
 542   return r;
 543 }
 544 \f
 545 /* Find the strings in file FILENAME, read from STREAM.
 546    Assume that STREAM is positioned so that the next byte read
 547    is at address ADDRESS in the file.
 548    Stop reading at address STOP_POINT in the file, if nonzero.
 549
 550    If STREAM is NULL, do not read from it.
 551    The caller can supply a buffer of characters
 552    to be processed before the data in STREAM.
 553    MAGIC is the address of the buffer and
 554    MAGICCOUNT is how many characters are in it.
 555    Those characters come at address ADDRESS and the data in STREAM follow.  */
 556
 557 static void
 558 print_strings (const char *filename, FILE *stream, file_off address,
 559                int stop_point, int magiccount, char *magic)
 560 {
 561   char *buf = (char *) xmalloc (sizeof (char) * (string_min + 1));
 562
 563   while (1)
 564     {
 565       file_off start;
 566       int i;
 567       long c;
 568
 569       /* See if the next `string_min' chars are all graphic chars.  */
 570     tryline:
 571       if (stop_point && address >= stop_point)
 572         break;
 573       start = address;
 574       for (i = 0; i < string_min; i++)
 575         {
 576           c = get_char (stream, &address, &magiccount, &magic);
 577           if (c == EOF)
 578             return;
 579           if (! STRING_ISGRAPHIC (c))
 580             /* Found a non-graphic.  Try again starting with next char.  */
 581             goto tryline;
 582           buf[i] = c;
 583         }
 584
 585       /* We found a run of `string_min' graphic characters.  Print up
 586          to the next non-graphic character.  */
 587
 588       if (print_filenames)
 589         printf ("%s: ", filename);
 590       if (print_addresses)
 591         switch (address_radix)
 592           {
 593           case 8:
 594 #if __STDC_VERSION__ >= 199901L || (defined(__GNUC__) && __GNUC__ >= 2)
 595             if (sizeof (start) > sizeof (long))
 596               printf ("%7Lo ", (unsigned long long) start);
 597             else
 598 #else
 599 # if !BFD_HOST_64BIT_LONG
 600             if (start != (unsigned long) start)
 601               printf ("++%7lo ", (unsigned long) start);
 602             else
 603 # endif
 604 #endif
 605               printf ("%7lo ", (unsigned long) start);
 606             break;
 607
 608           case 10:
 609 #if __STDC_VERSION__ >= 199901L || (defined(__GNUC__) && __GNUC__ >= 2)
 610             if (sizeof (start) > sizeof (long))
 611               printf ("%7Ld ", (unsigned long long) start);
 612             else
 613 #else
 614 # if !BFD_HOST_64BIT_LONG
 615             if (start != (unsigned long) start)
 616               printf ("++%7ld ", (unsigned long) start);
 617             else
 618 # endif
 619 #endif
 620               printf ("%7ld ", (long) start);
 621             break;
 622
 623           case 16:
 624 #if __STDC_VERSION__ >= 199901L || (defined(__GNUC__) && __GNUC__ >= 2)
 625             if (sizeof (start) > sizeof (long))
 626               printf ("%7Lx ", (unsigned long long) start);
 627             else
 628 #else
 629 # if !BFD_HOST_64BIT_LONG
 630             if (start != (unsigned long) start)
 631               printf ("%lx%8.8lx ", (unsigned long) (start >> 32),
 632                       (unsigned long) (start & 0xffffffff));
 633             else
 634 # endif
 635 #endif
 636               printf ("%7lx ", (unsigned long) start);
 637             break;
 638           }
 639
 640       buf[i] = '\0';
 641       fputs (buf, stdout);
 642
 643       while (1)
 644         {
 645           c = get_char (stream, &address, &magiccount, &magic);
 646           if (c == EOF)
 647             break;
 648           if (! STRING_ISGRAPHIC (c))
 649             break;
 650           putchar (c);
 651         }
 652
 653       putchar ('\n');
 654     }
 655 }
 656 \f
 657 /* Parse string S as an integer, using decimal radix by default,
 658    but allowing octal and hex numbers as in C.  */
 659
 660 static int
 661 integer_arg (char *s)
 662 {
 663   int value;
 664   int radix = 10;
 665   char *p = s;
 666   int c;
 667
 668   if (*p != '0')
 669     radix = 10;
 670   else if (*++p == 'x')
 671     {
 672       radix = 16;
 673       p++;
 674     }
 675   else
 676     radix = 8;
 677
 678   value = 0;
 679   while (((c = *p++) >= '0' && c <= '9')
 680          || (radix == 16 && (c & ~40) >= 'A' && (c & ~40) <= 'Z'))
 681     {
 682       value *= radix;
 683       if (c >= '0' && c <= '9')
 684         value += c - '0';
 685       else
 686         value += (c & ~40) - 'A';
 687     }
 688
 689   if (c == 'b')
 690     value *= 512;
 691   else if (c == 'B')
 692     value *= 1024;
 693   else
 694     p--;
 695
 696   if (*p)
 697     fatal (_("invalid integer argument %s"), s);
 698
 699   return value;
 700 }
 701
 702 static void
 703 usage (FILE *stream, int status)
 704 {
 705   fprintf (stream, _("Usage: %s [option(s)] [file(s)]\n"), program_name);
 706   fprintf (stream, _(" Display printable strings in [file(s)] (stdin by default)\n"));
 707   fprintf (stream, _(" The options are:\n\
 708   -a - --all                Scan the entire file, not just the data section\n\
 709   -f --print-file-name      Print the name of the file before each string\n\
 710   -n --bytes=[number]       Locate & print any NUL-terminated sequence of at\n\
 711   -<number>                 least [number] characters (default 4).\n\
 712   -t --radix={o,d,x}        Print the location of the string in base 8, 10 or 16\n\
 713   -o                        An alias for --radix=o\n\
 714   -T --target=<BFDNAME>     Specify the binary file format\n\
 715   -e --encoding={s,S,b,l,B,L} Select character size and endianness:\n\
 716                             s = 7-bit, S = 8-bit, {b,l} = 16-bit, {B,L} = 32-bit\n\
 717   @<file>                   Read options from <file>\n\
 718   -h --help                 Display this information\n\
 719   -v --version              Print the program's version number\n"));
 720   list_supported_targets (program_name, stream);
 721   if (REPORT_BUGS_TO[0] && status == 0)
 722     fprintf (stream, _("Report bugs to %s\n"), REPORT_BUGS_TO);
 723   exit (status);
 724 }