1 /* strings -- print the strings of printable characters in files 2 Copyright (C) 1993-2016 Free Software Foundation, Inc. 3 4 This program is free software; you can redistribute it and/or modify 5 it under the terms of the GNU General Public License as published by 6 the Free Software Foundation; either version 3, or (at your option) 7 any later version. 8 9 This program is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 GNU General Public License for more details. 13 14 You should have received a copy of the GNU General Public License 15 along with this program; if not, write to the Free Software 16 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 17 02110-1301, USA. */ 18 19 /* Usage: strings [options] file... 21 22 Options: 23 --all 24 -a 25 - Scan each file in its entirety. 26 27 --data 28 -d Scan only the initialized data section(s) of object files. 29 30 --print-file-name 31 -f Print the name of the file before each string. 32 33 --bytes=min-len 34 -n min-len 35 -min-len Print graphic char sequences, MIN-LEN or more bytes long, 36 that are followed by a NUL or a newline. Default is 4. 37 38 --radix={o,x,d} 39 -t {o,x,d} Print the offset within the file before each string, 40 in octal/hex/decimal. 41 42 --include-all-whitespace 43 -w By default tab and space are the only whitepace included in graphic 44 char sequences. This option considers all of isspace() valid. 45 46 -o Like -to. (Some other implementations have -o like -to, 47 others like -td. We chose one arbitrarily.) 48 49 --encoding={s,S,b,l,B,L} 50 -e {s,S,b,l,B,L} 51 Select character encoding: 7-bit-character, 8-bit-character, 52 bigendian 16-bit, littleendian 16-bit, bigendian 32-bit, 53 littleendian 32-bit. 54 55 --target=BFDNAME 56 -T {bfdname} 57 Specify a non-default object file format. 58 59 --output-separator=sep_string 60 -s sep_string String used to separate parsed strings in output. 61 Default is newline. 62 63 --help 64 -h Print the usage message on the standard output. 65 66 --version 67 -V 68 -v Print the program version number. 69 70 Written by Richard Stallman <rms (at) gnu.ai.mit.edu> 71 and David MacKenzie <djm (at) gnu.ai.mit.edu>. */ 72 73 #include "sysdep.h" 74 #include "bfd.h" 75 #include "getopt.h" 76 #include "libiberty.h" 77 #include "safe-ctype.h" 78 #include "bucomm.h" 79 80 #define STRING_ISGRAPHIC(c) \ 81 ( (c) >= 0 \ 82 && (c) <= 255 \ 83 && ((c) == '\t' || ISPRINT (c) || (encoding == 'S' && (c) > 127) \ 84 || (include_all_whitespace == TRUE && ISSPACE (c))) \ 85 ) 86 87 #ifndef errno 88 extern int errno; 89 #endif 90 91 /* The BFD section flags that identify an initialized data section. */ 92 #define DATA_FLAGS (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS) 93 94 /* Radix for printing addresses (must be 8, 10 or 16). */ 95 static int address_radix; 96 97 /* Minimum length of sequence of graphic chars to trigger output. */ 98 static int string_min; 99 100 /* Whether or not we include all whitespace as a graphic char. */ 101 static bfd_boolean include_all_whitespace; 102 103 /* TRUE means print address within file for each string. */ 104 static bfd_boolean print_addresses; 105 106 /* TRUE means print filename for each string. */ 107 static bfd_boolean print_filenames; 108 109 /* TRUE means for object files scan only the data section. */ 110 static bfd_boolean datasection_only; 111 112 /* TRUE if we found an initialized data section in the current file. */ 113 static bfd_boolean got_a_section; 114 115 /* The BFD object file format. */ 116 static char *target; 117 118 /* The character encoding format. */ 119 static char encoding; 120 static int encoding_bytes; 121 122 /* Output string used to separate parsed strings */ 123 static char *output_separator; 124 125 static struct option long_options[] = 126 { 127 {"all", no_argument, NULL, 'a'}, 128 {"data", no_argument, NULL, 'd'}, 129 {"print-file-name", no_argument, NULL, 'f'}, 130 {"bytes", required_argument, NULL, 'n'}, 131 {"radix", required_argument, NULL, 't'}, 132 {"include-all-whitespace", required_argument, NULL, 'w'}, 133 {"encoding", required_argument, NULL, 'e'}, 134 {"target", required_argument, NULL, 'T'}, 135 {"output-separator", required_argument, NULL, 's'}, 136 {"help", no_argument, NULL, 'h'}, 137 {"version", no_argument, NULL, 'v'}, 138 {NULL, 0, NULL, 0} 139 }; 140 141 /* Records the size of a named file so that we 142 do not repeatedly run bfd_stat() on it. */ 143 144 typedef struct 145 { 146 const char * filename; 147 bfd_size_type filesize; 148 } filename_and_size_t; 149 150 static void strings_a_section (bfd *, asection *, void *); 151 static bfd_boolean strings_object_file (const char *); 152 static bfd_boolean strings_file (char *); 153 static void print_strings (const char *, FILE *, file_ptr, int, int, char *); 154 static void usage (FILE *, int); 155 static long get_char (FILE *, file_ptr *, int *, char **); 156 157 int main (int, char **); 159 160 int 161 main (int argc, char **argv) 162 { 163 int optc; 164 int exit_status = 0; 165 bfd_boolean files_given = FALSE; 166 char *s; 167 int numeric_opt = 0; 168 169 #if defined (HAVE_SETLOCALE) 170 setlocale (LC_ALL, ""); 171 #endif 172 bindtextdomain (PACKAGE, LOCALEDIR); 173 textdomain (PACKAGE); 174 175 program_name = argv[0]; 176 xmalloc_set_program_name (program_name); 177 bfd_set_error_program_name (program_name); 178 179 expandargv (&argc, &argv); 180 181 string_min = 4; 182 include_all_whitespace = FALSE; 183 print_addresses = FALSE; 184 print_filenames = FALSE; 185 if (DEFAULT_STRINGS_ALL) 186 datasection_only = FALSE; 187 else 188 datasection_only = TRUE; 189 target = NULL; 190 encoding = 's'; 191 output_separator = NULL; 192 193 while ((optc = getopt_long (argc, argv, "adfhHn:wot:e:T:s:Vv0123456789", 194 long_options, (int *) 0)) != EOF) 195 { 196 switch (optc) 197 { 198 case 'a': 199 datasection_only = FALSE; 200 break; 201 202 case 'd': 203 datasection_only = TRUE; 204 break; 205 206 case 'f': 207 print_filenames = TRUE; 208 break; 209 210 case 'H': 211 case 'h': 212 usage (stdout, 0); 213 214 case 'n': 215 string_min = (int) strtoul (optarg, &s, 0); 216 if (s != NULL && *s != 0) 217 fatal (_("invalid integer argument %s"), optarg); 218 break; 219 220 case 'w': 221 include_all_whitespace = TRUE; 222 break; 223 224 case 'o': 225 print_addresses = TRUE; 226 address_radix = 8; 227 break; 228 229 case 't': 230 print_addresses = TRUE; 231 if (optarg[1] != '\0') 232 usage (stderr, 1); 233 switch (optarg[0]) 234 { 235 case 'o': 236 address_radix = 8; 237 break; 238 239 case 'd': 240 address_radix = 10; 241 break; 242 243 case 'x': 244 address_radix = 16; 245 break; 246 247 default: 248 usage (stderr, 1); 249 } 250 break; 251 252 case 'T': 253 target = optarg; 254 break; 255 256 case 'e': 257 if (optarg[1] != '\0') 258 usage (stderr, 1); 259 encoding = optarg[0]; 260 break; 261 262 case 's': 263 output_separator = optarg; 264 break; 265 266 case 'V': 267 case 'v': 268 print_version ("strings"); 269 break; 270 271 case '?': 272 usage (stderr, 1); 273 274 default: 275 numeric_opt = optind; 276 break; 277 } 278 } 279 280 if (numeric_opt != 0) 281 { 282 string_min = (int) strtoul (argv[numeric_opt - 1] + 1, &s, 0); 283 if (s != NULL && *s != 0) 284 fatal (_("invalid integer argument %s"), argv[numeric_opt - 1] + 1); 285 } 286 if (string_min < 1) 287 fatal (_("invalid minimum string length %d"), string_min); 288 289 switch (encoding) 290 { 291 case 'S': 292 case 's': 293 encoding_bytes = 1; 294 break; 295 case 'b': 296 case 'l': 297 encoding_bytes = 2; 298 break; 299 case 'B': 300 case 'L': 301 encoding_bytes = 4; 302 break; 303 default: 304 usage (stderr, 1); 305 } 306 307 bfd_init (); 308 set_default_bfd_target (); 309 310 if (optind >= argc) 311 { 312 datasection_only = FALSE; 313 SET_BINARY (fileno (stdin)); 314 print_strings ("{standard input}", stdin, 0, 0, 0, (char *) NULL); 315 files_given = TRUE; 316 } 317 else 318 { 319 for (; optind < argc; ++optind) 320 { 321 if (strcmp (argv[optind], "-") == 0) 322 datasection_only = FALSE; 323 else 324 { 325 files_given = TRUE; 326 exit_status |= strings_file (argv[optind]) == FALSE; 327 } 328 } 329 } 330 331 if (!files_given) 332 usage (stderr, 1); 333 334 return (exit_status); 335 } 336 337 /* Scan section SECT of the file ABFD, whose printable name is in 339 ARG->filename and whose size might be in ARG->filesize. If it 340 contains initialized data set `got_a_section' and print the 341 strings in it. 342 343 FIXME: We ought to be able to return error codes/messages for 344 certain conditions. */ 345 346 static void 347 strings_a_section (bfd *abfd, asection *sect, void *arg) 348 { 349 filename_and_size_t * filename_and_sizep; 350 bfd_size_type *filesizep; 351 bfd_size_type sectsize; 352 void *mem; 353 354 if ((sect->flags & DATA_FLAGS) != DATA_FLAGS) 355 return; 356 357 sectsize = bfd_get_section_size (sect); 358 359 if (sectsize <= 0) 360 return; 361 362 /* Get the size of the file. This might have been cached for us. */ 363 filename_and_sizep = (filename_and_size_t *) arg; 364 filesizep = & filename_and_sizep->filesize; 365 366 if (*filesizep == 0) 367 { 368 struct stat st; 369 370 if (bfd_stat (abfd, &st)) 371 return; 372 373 /* Cache the result so that we do not repeatedly stat this file. */ 374 *filesizep = st.st_size; 375 } 376 377 /* Compare the size of the section against the size of the file. 378 If the section is bigger then the file must be corrupt and 379 we should not try dumping it. */ 380 if (sectsize >= *filesizep) 381 return; 382 383 mem = xmalloc (sectsize); 384 385 if (bfd_get_section_contents (abfd, sect, mem, (file_ptr) 0, sectsize)) 386 { 387 got_a_section = TRUE; 388 389 print_strings (filename_and_sizep->filename, NULL, sect->filepos, 390 0, sectsize, (char *) mem); 391 } 392 393 free (mem); 394 } 395 396 /* Scan all of the sections in FILE, and print the strings 397 in the initialized data section(s). 398 399 Return TRUE if successful, 400 FALSE if not (such as if FILE is not an object file). */ 401 402 static bfd_boolean 403 strings_object_file (const char *file) 404 { 405 filename_and_size_t filename_and_size; 406 bfd *abfd; 407 408 abfd = bfd_openr (file, target); 409 410 if (abfd == NULL) 411 /* Treat the file as a non-object file. */ 412 return FALSE; 413 414 /* This call is mainly for its side effect of reading in the sections. 415 We follow the traditional behavior of `strings' in that we don't 416 complain if we don't recognize a file to be an object file. */ 417 if (!bfd_check_format (abfd, bfd_object)) 418 { 419 bfd_close (abfd); 420 return FALSE; 421 } 422 423 got_a_section = FALSE; 424 filename_and_size.filename = file; 425 filename_and_size.filesize = 0; 426 bfd_map_over_sections (abfd, strings_a_section, & filename_and_size); 427 428 if (!bfd_close (abfd)) 429 { 430 bfd_nonfatal (file); 431 return FALSE; 432 } 433 434 return got_a_section; 435 } 436 437 /* Print the strings in FILE. Return TRUE if ok, FALSE if an error occurs. */ 438 439 static bfd_boolean 440 strings_file (char *file) 441 { 442 struct stat st; 443 444 /* get_file_size does not support non-S_ISREG files. */ 445 446 if (stat (file, &st) < 0) 447 { 448 if (errno == ENOENT) 449 non_fatal (_("'%s': No such file"), file); 450 else 451 non_fatal (_("Warning: could not locate '%s'. reason: %s"), 452 file, strerror (errno)); 453 return FALSE; 454 } 455 456 /* If we weren't told to scan the whole file, 457 try to open it as an object file and only look at 458 initialized data sections. If that fails, fall back to the 459 whole file. */ 460 if (!datasection_only || !strings_object_file (file)) 461 { 462 FILE *stream; 463 464 stream = fopen (file, FOPEN_RB); 465 if (stream == NULL) 466 { 467 fprintf (stderr, "%s: ", program_name); 468 perror (file); 469 return FALSE; 470 } 471 472 print_strings (file, stream, (file_ptr) 0, 0, 0, (char *) 0); 473 474 if (fclose (stream) == EOF) 475 { 476 fprintf (stderr, "%s: ", program_name); 477 perror (file); 478 return FALSE; 479 } 480 } 481 482 return TRUE; 483 } 484 485 /* Read the next character, return EOF if none available. 487 Assume that STREAM is positioned so that the next byte read 488 is at address ADDRESS in the file. 489 490 If STREAM is NULL, do not read from it. 491 The caller can supply a buffer of characters 492 to be processed before the data in STREAM. 493 MAGIC is the address of the buffer and 494 MAGICCOUNT is how many characters are in it. */ 495 496 static long 497 get_char (FILE *stream, file_ptr *address, int *magiccount, char **magic) 498 { 499 int c, i; 500 long r = 0; 501 502 for (i = 0; i < encoding_bytes; i++) 503 { 504 if (*magiccount) 505 { 506 (*magiccount)--; 507 c = *(*magic)++; 508 } 509 else 510 { 511 if (stream == NULL) 512 return EOF; 513 514 /* Only use getc_unlocked if we found a declaration for it. 515 Otherwise, libc is not thread safe by default, and we 516 should not use it. */ 517 518 #if defined(HAVE_GETC_UNLOCKED) && HAVE_DECL_GETC_UNLOCKED 519 c = getc_unlocked (stream); 520 #else 521 c = getc (stream); 522 #endif 523 if (c == EOF) 524 return EOF; 525 } 526 527 (*address)++; 528 r = (r << 8) | (c & 0xff); 529 } 530 531 switch (encoding) 532 { 533 default: 534 break; 535 case 'l': 536 r = ((r & 0xff) << 8) | ((r & 0xff00) >> 8); 537 break; 538 case 'L': 539 r = (((r & 0xff) << 24) | ((r & 0xff00) << 8) 540 | ((r & 0xff0000) >> 8) | ((r & 0xff000000) >> 24)); 541 break; 542 } 543 544 return r; 545 } 546 547 /* Find the strings in file FILENAME, read from STREAM. 549 Assume that STREAM is positioned so that the next byte read 550 is at address ADDRESS in the file. 551 Stop reading at address STOP_POINT in the file, if nonzero. 552 553 If STREAM is NULL, do not read from it. 554 The caller can supply a buffer of characters 555 to be processed before the data in STREAM. 556 MAGIC is the address of the buffer and 557 MAGICCOUNT is how many characters are in it. 558 Those characters come at address ADDRESS and the data in STREAM follow. */ 559 560 static void 561 print_strings (const char *filename, FILE *stream, file_ptr address, 562 int stop_point, int magiccount, char *magic) 563 { 564 char *buf = (char *) xmalloc (sizeof (char) * (string_min + 1)); 565 566 while (1) 567 { 568 file_ptr start; 569 int i; 570 long c; 571 572 /* See if the next `string_min' chars are all graphic chars. */ 573 tryline: 574 if (stop_point && address >= stop_point) 575 break; 576 start = address; 577 for (i = 0; i < string_min; i++) 578 { 579 c = get_char (stream, &address, &magiccount, &magic); 580 if (c == EOF) 581 { 582 free (buf); 583 return; 584 } 585 if (! STRING_ISGRAPHIC (c)) 586 /* Found a non-graphic. Try again starting with next char. */ 587 goto tryline; 588 buf[i] = c; 589 } 590 591 /* We found a run of `string_min' graphic characters. Print up 592 to the next non-graphic character. */ 593 594 if (print_filenames) 595 printf ("%s: ", filename); 596 if (print_addresses) 597 switch (address_radix) 598 { 599 case 8: 600 #ifdef HAVE_LONG_LONG 601 if (sizeof (start) > sizeof (long)) 602 { 603 # ifndef __MSVCRT__ 604 printf ("%7llo ", (unsigned long long) start); 605 # else 606 printf ("%7I64o ", (unsigned long long) start); 607 # endif 608 } 609 else 610 #elif !BFD_HOST_64BIT_LONG 611 if (start != (unsigned long) start) 612 printf ("++%7lo ", (unsigned long) start); 613 else 614 #endif 615 printf ("%7lo ", (unsigned long) start); 616 break; 617 618 case 10: 619 #ifdef HAVE_LONG_LONG 620 if (sizeof (start) > sizeof (long)) 621 { 622 # ifndef __MSVCRT__ 623 printf ("%7lld ", (unsigned long long) start); 624 # else 625 printf ("%7I64d ", (unsigned long long) start); 626 # endif 627 } 628 else 629 #elif !BFD_HOST_64BIT_LONG 630 if (start != (unsigned long) start) 631 printf ("++%7ld ", (unsigned long) start); 632 else 633 #endif 634 printf ("%7ld ", (long) start); 635 break; 636 637 case 16: 638 #ifdef HAVE_LONG_LONG 639 if (sizeof (start) > sizeof (long)) 640 { 641 # ifndef __MSVCRT__ 642 printf ("%7llx ", (unsigned long long) start); 643 # else 644 printf ("%7I64x ", (unsigned long long) start); 645 # endif 646 } 647 else 648 #elif !BFD_HOST_64BIT_LONG 649 if (start != (unsigned long) start) 650 printf ("%lx%8.8lx ", (unsigned long) (start >> 32), 651 (unsigned long) (start & 0xffffffff)); 652 else 653 #endif 654 printf ("%7lx ", (unsigned long) start); 655 break; 656 } 657 658 buf[i] = '\0'; 659 fputs (buf, stdout); 660 661 while (1) 662 { 663 c = get_char (stream, &address, &magiccount, &magic); 664 if (c == EOF) 665 break; 666 if (! STRING_ISGRAPHIC (c)) 667 break; 668 putchar (c); 669 } 670 671 if (output_separator) 672 fputs (output_separator, stdout); 673 else 674 putchar ('\n'); 675 } 676 free (buf); 677 } 678 679 static void 681 usage (FILE *stream, int status) 682 { 683 fprintf (stream, _("Usage: %s [option(s)] [file(s)]\n"), program_name); 684 fprintf (stream, _(" Display printable strings in [file(s)] (stdin by default)\n")); 685 fprintf (stream, _(" The options are:\n")); 686 687 if (DEFAULT_STRINGS_ALL) 688 fprintf (stream, _("\ 689 -a - --all Scan the entire file, not just the data section [default]\n\ 690 -d --data Only scan the data sections in the file\n")); 691 else 692 fprintf (stream, _("\ 693 -a - --all Scan the entire file, not just the data section\n\ 694 -d --data Only scan the data sections in the file [default]\n")); 695 696 fprintf (stream, _("\ 697 -f --print-file-name Print the name of the file before each string\n\ 698 -n --bytes=[number] Locate & print any NUL-terminated sequence of at\n\ 699 -<number> least [number] characters (default 4).\n\ 700 -t --radix={o,d,x} Print the location of the string in base 8, 10 or 16\n\ 701 -w --include-all-whitespace Include all whitespace as valid string characters\n\ 702 -o An alias for --radix=o\n\ 703 -T --target=<BFDNAME> Specify the binary file format\n\ 704 -e --encoding={s,S,b,l,B,L} Select character size and endianness:\n\ 705 s = 7-bit, S = 8-bit, {b,l} = 16-bit, {B,L} = 32-bit\n\ 706 -s --output-separator=<string> String used to separate strings in output.\n\ 707 @<file> Read options from <file>\n\ 708 -h --help Display this information\n\ 709 -v -V --version Print the program's version number\n")); 710 list_supported_targets (program_name, stream); 711 if (REPORT_BUGS_TO[0] && status == 0) 712 fprintf (stream, _("Report bugs to %s\n"), REPORT_BUGS_TO); 713 exit (status); 714 } 715
