src/md5sum.c

   1 /* Compute MD5, SHA1, SHA224, SHA256, SHA384 or SHA512 checksum of files or strings
   2    Copyright (C) 1995-2009 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 of the License, or
   7    (at your option) 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, see <http://www.gnu.org/licenses/>.  */
  16
  17 /* Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>.  */
  18
  19 #include <config.h>
  20
  21 #include <getopt.h>
  22 #include <sys/types.h>
  23
  24 #include "system.h"
  25
  26 #if HASH_ALGO_MD5
  27 # include "md5.h"
  28 #endif
  29 #if HASH_ALGO_SHA1
  30 # include "sha1.h"
  31 #endif
  32 #if HASH_ALGO_SHA256 || HASH_ALGO_SHA224
  33 # include "sha256.h"
  34 #endif
  35 #if HASH_ALGO_SHA512 || HASH_ALGO_SHA384
  36 # include "sha512.h"
  37 #endif
  38 #include "error.h"
  39 #include "stdio--.h"
  40 #include "xfreopen.h"
  41
  42 /* The official name of this program (e.g., no `g' prefix).  */
  43 #if HASH_ALGO_MD5
  44 # define PROGRAM_NAME "md5sum"
  45 # define DIGEST_TYPE_STRING "MD5"
  46 # define DIGEST_STREAM md5_stream
  47 # define DIGEST_BITS 128
  48 # define DIGEST_REFERENCE "RFC 1321"
  49 # define DIGEST_ALIGN 4
  50 #elif HASH_ALGO_SHA1
  51 # define PROGRAM_NAME "sha1sum"
  52 # define DIGEST_TYPE_STRING "SHA1"
  53 # define DIGEST_STREAM sha1_stream
  54 # define DIGEST_BITS 160
  55 # define DIGEST_REFERENCE "FIPS-180-1"
  56 # define DIGEST_ALIGN 4
  57 #elif HASH_ALGO_SHA256
  58 # define PROGRAM_NAME "sha256sum"
  59 # define DIGEST_TYPE_STRING "SHA256"
  60 # define DIGEST_STREAM sha256_stream
  61 # define DIGEST_BITS 256
  62 # define DIGEST_REFERENCE "FIPS-180-2"
  63 # define DIGEST_ALIGN 4
  64 #elif HASH_ALGO_SHA224
  65 # define PROGRAM_NAME "sha224sum"
  66 # define DIGEST_TYPE_STRING "SHA224"
  67 # define DIGEST_STREAM sha224_stream
  68 # define DIGEST_BITS 224
  69 # define DIGEST_REFERENCE "RFC 3874"
  70 # define DIGEST_ALIGN 4
  71 #elif HASH_ALGO_SHA512
  72 # define PROGRAM_NAME "sha512sum"
  73 # define DIGEST_TYPE_STRING "SHA512"
  74 # define DIGEST_STREAM sha512_stream
  75 # define DIGEST_BITS 512
  76 # define DIGEST_REFERENCE "FIPS-180-2"
  77 # define DIGEST_ALIGN 8
  78 #elif HASH_ALGO_SHA384
  79 # define PROGRAM_NAME "sha384sum"
  80 # define DIGEST_TYPE_STRING "SHA384"
  81 # define DIGEST_STREAM sha384_stream
  82 # define DIGEST_BITS 384
  83 # define DIGEST_REFERENCE "FIPS-180-2"
  84 # define DIGEST_ALIGN 8
  85 #else
  86 # error "Can't decide which hash algorithm to compile."
  87 #endif
  88
  89 #define DIGEST_HEX_BYTES (DIGEST_BITS / 4)
  90 #define DIGEST_BIN_BYTES (DIGEST_BITS / 8)
  91
  92 #define AUTHORS \
  93   proper_name ("Ulrich Drepper"), \
  94   proper_name ("Scott Miller"), \
  95   proper_name ("David Madore")
  96
  97 /* The minimum length of a valid digest line.  This length does
  98    not include any newline character at the end of a line.  */
  99 #define MIN_DIGEST_LINE_LENGTH \
 100   (DIGEST_HEX_BYTES /* length of hexadecimal message digest */ \
 101    + 2 /* blank and binary indicator */ \
 102    + 1 /* minimum filename length */ )
 103
 104 /* True if any of the files read were the standard input. */
 105 static bool have_read_stdin;
 106
 107 /* The minimum length of a valid checksum line for the selected algorithm.  */
 108 static size_t min_digest_line_length;
 109
 110 /* Set to the length of a digest hex string for the selected algorithm.  */
 111 static size_t digest_hex_bytes;
 112
 113 /* With --check, don't generate any output.
 114    The exit code indicates success or failure.  */
 115 static bool status_only = false;
 116
 117 /* With --check, print a message to standard error warning about each
 118    improperly formatted checksum line.  */
 119 static bool warn = false;
 120
 121 /* With --check, suppress the "OK" printed for each verified file.  */
 122 static bool quiet = false;
 123
 124 /* For long options that have no equivalent short option, use a
 125    non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
 126 enum
 127 {
 128   STATUS_OPTION = CHAR_MAX + 1,
 129   QUIET_OPTION
 130 };
 131
 132 static struct option const long_options[] =
 133 {
 134   { "binary", no_argument, NULL, 'b' },
 135   { "check", no_argument, NULL, 'c' },
 136   { "quiet", no_argument, NULL, QUIET_OPTION },
 137   { "status", no_argument, NULL, STATUS_OPTION },
 138   { "text", no_argument, NULL, 't' },
 139   { "warn", no_argument, NULL, 'w' },
 140   { GETOPT_HELP_OPTION_DECL },
 141   { GETOPT_VERSION_OPTION_DECL },
 142   { NULL, 0, NULL, 0 }
 143 };
 144
 145 void
 146 usage (int status)
 147 {
 148   if (status != EXIT_SUCCESS)
 149     fprintf (stderr, _("Try `%s --help' for more information.\n"),
 150              program_name);
 151   else
 152     {
 153       printf (_("\
 154 Usage: %s [OPTION]... [FILE]...\n\
 155 Print or check %s (%d-bit) checksums.\n\
 156 With no FILE, or when FILE is -, read standard input.\n\
 157 \n\
 158 "),
 159               program_name,
 160               DIGEST_TYPE_STRING,
 161               DIGEST_BITS);
 162       if (O_BINARY)
 163         fputs (_("\
 164   -b, --binary            read in binary mode (default unless reading tty stdin)\n\
 165 "), stdout);
 166       else
 167         fputs (_("\
 168   -b, --binary            read in binary mode\n\
 169 "), stdout);
 170       printf (_("\
 171   -c, --check             read %s sums from the FILEs and check them\n"),
 172               DIGEST_TYPE_STRING);
 173       if (O_BINARY)
 174         fputs (_("\
 175   -t, --text              read in text mode (default if reading tty stdin)\n\
 176 "), stdout);
 177       else
 178         fputs (_("\
 179   -t, --text              read in text mode (default)\n\
 180 "), stdout);
 181       fputs (_("\
 182 \n\
 183 The following three options are useful only when verifying checksums:\n\
 184       --quiet             don't print OK for each successfully verified file\n\
 185       --status            don't output anything, status code shows success\n\
 186   -w, --warn              warn about improperly formatted checksum lines\n\
 187 \n\
 188 "), stdout);
 189       fputs (HELP_OPTION_DESCRIPTION, stdout);
 190       fputs (VERSION_OPTION_DESCRIPTION, stdout);
 191       printf (_("\
 192 \n\
 193 The sums are computed as described in %s.  When checking, the input\n\
 194 should be a former output of this program.  The default mode is to print\n\
 195 a line with checksum, a character indicating type (`*' for binary, ` ' for\n\
 196 text), and name for each FILE.\n"),
 197               DIGEST_REFERENCE);
 198       emit_bug_reporting_address ();
 199     }
 200
 201   exit (status);
 202 }
 203
 204 #define ISWHITE(c) ((c) == ' ' || (c) == '\t')
 205
 206 /* Split the checksum string S (of length S_LEN) from a BSD 'md5' or
 207    'sha1' command into two parts: a hexadecimal digest, and the file
 208    name.  S is modified.  Return true if successful.  */
 209
 210 static bool
 211 bsd_split_3 (char *s, size_t s_len, unsigned char **hex_digest, char **file_name)
 212 {
 213   size_t i;
 214
 215   if (s_len == 0)
 216     return false;
 217
 218   *file_name = s;
 219
 220   /* Find end of filename. The BSD 'md5' and 'sha1' commands do not escape
 221      filenames, so search backwards for the last ')'. */
 222   i = s_len - 1;
 223   while (i && s[i] != ')')
 224     i--;
 225
 226   if (s[i] != ')')
 227     return false;
 228
 229   s[i++] = '\0';
 230
 231   while (ISWHITE (s[i]))
 232     i++;
 233
 234   if (s[i] != '=')
 235     return false;
 236
 237   i++;
 238
 239   while (ISWHITE (s[i]))
 240     i++;
 241
 242   *hex_digest = (unsigned char *) &s[i];
 243   return true;
 244 }
 245
 246 /* Split the string S (of length S_LEN) into three parts:
 247    a hexadecimal digest, binary flag, and the file name.
 248    S is modified.  Return true if successful.  */
 249
 250 static bool
 251 split_3 (char *s, size_t s_len,
 252          unsigned char **hex_digest, int *binary, char **file_name)
 253 {
 254   size_t i;
 255   bool escaped_filename = false;
 256   size_t algo_name_len;
 257
 258   i = 0;
 259   while (ISWHITE (s[i]))
 260     ++i;
 261
 262   /* Check for BSD-style checksum line. */
 263   algo_name_len = strlen (DIGEST_TYPE_STRING);
 264   if (strncmp (s + i, DIGEST_TYPE_STRING, algo_name_len) == 0)
 265     {
 266       if (strncmp (s + i + algo_name_len, " (", 2) == 0)
 267         {
 268           *binary = 0;
 269           return bsd_split_3 (s +      i + algo_name_len + 2,
 270                               s_len - (i + algo_name_len + 2),
 271                               hex_digest, file_name);
 272         }
 273     }
 274
 275   /* Ignore this line if it is too short.
 276      Each line must have at least `min_digest_line_length - 1' (or one more, if
 277      the first is a backslash) more characters to contain correct message digest
 278      information.  */
 279   if (s_len - i < min_digest_line_length + (s[i] == '\\'))
 280     return false;
 281
 282   if (s[i] == '\\')
 283     {
 284       ++i;
 285       escaped_filename = true;
 286     }
 287   *hex_digest = (unsigned char *) &s[i];
 288
 289   /* The first field has to be the n-character hexadecimal
 290      representation of the message digest.  If it is not followed
 291      immediately by a white space it's an error.  */
 292   i += digest_hex_bytes;
 293   if (!ISWHITE (s[i]))
 294     return false;
 295
 296   s[i++] = '\0';
 297
 298   if (s[i] != ' ' && s[i] != '*')
 299     return false;
 300   *binary = (s[i++] == '*');
 301
 302   /* All characters between the type indicator and end of line are
 303      significant -- that includes leading and trailing white space.  */
 304   *file_name = &s[i];
 305
 306   if (escaped_filename)
 307     {
 308       /* Translate each `\n' string in the file name to a NEWLINE,
 309          and each `\\' string to a backslash.  */
 310
 311       char *dst = &s[i];
 312
 313       while (i < s_len)
 314         {
 315           switch (s[i])
 316             {
 317             case '\\':
 318               if (i == s_len - 1)
 319                 {
 320                   /* A valid line does not end with a backslash.  */
 321                   return false;
 322                 }
 323               ++i;
 324               switch (s[i++])
 325                 {
 326                 case 'n':
 327                   *dst++ = '\n';
 328                   break;
 329                 case '\\':
 330                   *dst++ = '\\';
 331                   break;
 332                 default:
 333                   /* Only `\' or `n' may follow a backslash.  */
 334                   return false;
 335                 }
 336               break;
 337
 338             case '\0':
 339               /* The file name may not contain a NUL.  */
 340               return false;
 341               break;
 342
 343             default:
 344               *dst++ = s[i++];
 345               break;
 346             }
 347         }
 348       *dst = '\0';
 349     }
 350   return true;
 351 }
 352
 353 /* Return true if S is a NUL-terminated string of DIGEST_HEX_BYTES hex digits.
 354    Otherwise, return false.  */
 355 static bool
 356 hex_digits (unsigned char const *s)
 357 {
 358   unsigned int i;
 359   for (i = 0; i < digest_hex_bytes; i++)
 360     {
 361       if (!isxdigit (*s))
 362         return false;
 363       ++s;
 364     }
 365   return *s == '\0';
 366 }
 367
 368 /* An interface to the function, DIGEST_STREAM.
 369    Operate on FILENAME (it may be "-").
 370
 371    *BINARY indicates whether the file is binary.  BINARY < 0 means it
 372    depends on whether binary mode makes any difference and the file is
 373    a terminal; in that case, clear *BINARY if the file was treated as
 374    text because it was a terminal.
 375
 376    Put the checksum in *BIN_RESULT, which must be properly aligned.
 377    Return true if successful.  */
 378
 379 static bool
 380 digest_file (const char *filename, int *binary, unsigned char *bin_result)
 381 {
 382   FILE *fp;
 383   int err;
 384   bool is_stdin = STREQ (filename, "-");
 385
 386   if (is_stdin)
 387     {
 388       have_read_stdin = true;
 389       fp = stdin;
 390       if (O_BINARY && *binary)
 391         {
 392           if (*binary < 0)
 393             *binary = ! isatty (STDIN_FILENO);
 394           if (*binary)
 395             xfreopen (NULL, "rb", stdin);
 396         }
 397     }
 398   else
 399     {
 400       fp = fopen (filename, (O_BINARY && *binary ? "rb" : "r"));
 401       if (fp == NULL)
 402         {
 403           error (0, errno, "%s", filename);
 404           return false;
 405         }
 406     }
 407
 408   err = DIGEST_STREAM (fp, bin_result);
 409   if (err)
 410     {
 411       error (0, errno, "%s", filename);
 412       if (fp != stdin)
 413         fclose (fp);
 414       return false;
 415     }
 416
 417   if (!is_stdin && fclose (fp) != 0)
 418     {
 419       error (0, errno, "%s", filename);
 420       return false;
 421     }
 422
 423   return true;
 424 }
 425
 426 static bool
 427 digest_check (const char *checkfile_name)
 428 {
 429   FILE *checkfile_stream;
 430   uintmax_t n_properly_formatted_lines = 0;
 431   uintmax_t n_mismatched_checksums = 0;
 432   uintmax_t n_open_or_read_failures = 0;
 433   unsigned char bin_buffer_unaligned[DIGEST_BIN_BYTES + DIGEST_ALIGN];
 434   /* Make sure bin_buffer is properly aligned. */
 435   unsigned char *bin_buffer = ptr_align (bin_buffer_unaligned, DIGEST_ALIGN);
 436   uintmax_t line_number;
 437   char *line;
 438   size_t line_chars_allocated;
 439   bool is_stdin = STREQ (checkfile_name, "-");
 440
 441   if (is_stdin)
 442     {
 443       have_read_stdin = true;
 444       checkfile_name = _("standard input");
 445       checkfile_stream = stdin;
 446     }
 447   else
 448     {
 449       checkfile_stream = fopen (checkfile_name, "r");
 450       if (checkfile_stream == NULL)
 451         {
 452           error (0, errno, "%s", checkfile_name);
 453           return false;
 454         }
 455     }
 456
 457   line_number = 0;
 458   line = NULL;
 459   line_chars_allocated = 0;
 460   do
 461     {
 462       char *filename IF_LINT (= NULL);
 463       int binary;
 464       unsigned char *hex_digest IF_LINT (= NULL);
 465       ssize_t line_length;
 466
 467       ++line_number;
 468       if (line_number == 0)
 469         error (EXIT_FAILURE, 0, _("%s: too many checksum lines"),
 470                checkfile_name);
 471
 472       line_length = getline (&line, &line_chars_allocated, checkfile_stream);
 473       if (line_length <= 0)
 474         break;
 475
 476       /* Ignore comment lines, which begin with a '#' character.  */
 477       if (line[0] == '#')
 478         continue;
 479
 480       /* Remove any trailing newline.  */
 481       if (line[line_length - 1] == '\n')
 482         line[--line_length] = '\0';
 483
 484       if (! (split_3 (line, line_length, &hex_digest, &binary, &filename)
 485              && ! (is_stdin && STREQ (filename, "-"))
 486              && hex_digits (hex_digest)))
 487         {
 488           if (warn)
 489             {
 490               error (0, 0,
 491                      _("%s: %" PRIuMAX
 492                        ": improperly formatted %s checksum line"),
 493                      checkfile_name, line_number,
 494                      DIGEST_TYPE_STRING);
 495             }
 496         }
 497       else
 498         {
 499           static const char bin2hex[] = { '0', '1', '2', '3',
 500                                           '4', '5', '6', '7',
 501                                           '8', '9', 'a', 'b',
 502                                           'c', 'd', 'e', 'f' };
 503           bool ok;
 504
 505           ++n_properly_formatted_lines;
 506
 507           ok = digest_file (filename, &binary, bin_buffer);
 508
 509           if (!ok)
 510             {
 511               ++n_open_or_read_failures;
 512               if (!status_only)
 513                 {
 514                   printf (_("%s: FAILED open or read\n"), filename);
 515                   fflush (stdout);
 516                 }
 517             }
 518           else
 519             {
 520               size_t digest_bin_bytes = digest_hex_bytes / 2;
 521               size_t cnt;
 522               /* Compare generated binary number with text representation
 523                  in check file.  Ignore case of hex digits.  */
 524               for (cnt = 0; cnt < digest_bin_bytes; ++cnt)
 525                 {
 526                   if (tolower (hex_digest[2 * cnt])
 527                       != bin2hex[bin_buffer[cnt] >> 4]
 528                       || (tolower (hex_digest[2 * cnt + 1])
 529                           != (bin2hex[bin_buffer[cnt] & 0xf])))
 530                     break;
 531                 }
 532               if (cnt != digest_bin_bytes)
 533                 ++n_mismatched_checksums;
 534
 535               if (!status_only)
 536                 {
 537                   if (cnt != digest_bin_bytes)
 538                     printf ("%s: %s\n", filename, _("FAILED"));
 539                   else if (!quiet)
 540                     printf ("%s: %s\n", filename, _("OK"));
 541                   fflush (stdout);
 542                 }
 543             }
 544         }
 545     }
 546   while (!feof (checkfile_stream) && !ferror (checkfile_stream));
 547
 548   free (line);
 549
 550   if (ferror (checkfile_stream))
 551     {
 552       error (0, 0, _("%s: read error"), checkfile_name);
 553       return false;
 554     }
 555
 556   if (!is_stdin && fclose (checkfile_stream) != 0)
 557     {
 558       error (0, errno, "%s", checkfile_name);
 559       return false;
 560     }
 561
 562   if (n_properly_formatted_lines == 0)
 563     {
 564       /* Warn if no tests are found.  */
 565       error (0, 0, _("%s: no properly formatted %s checksum lines found"),
 566              checkfile_name, DIGEST_TYPE_STRING);
 567     }
 568   else
 569     {
 570       if (!status_only)
 571         {
 572           if (n_open_or_read_failures != 0)
 573             error (0, 0,
 574                    ngettext ("WARNING: %" PRIuMAX " of %" PRIuMAX
 575                              " listed file could not be read",
 576                              "WARNING: %" PRIuMAX " of %" PRIuMAX
 577                              " listed files could not be read",
 578                              select_plural (n_properly_formatted_lines)),
 579                    n_open_or_read_failures, n_properly_formatted_lines);
 580
 581           if (n_mismatched_checksums != 0)
 582             {
 583               uintmax_t n_computed_checksums =
 584                 (n_properly_formatted_lines - n_open_or_read_failures);
 585               error (0, 0,
 586                      ngettext ("WARNING: %" PRIuMAX " of %" PRIuMAX
 587                                " computed checksum did NOT match",
 588                                "WARNING: %" PRIuMAX " of %" PRIuMAX
 589                                " computed checksums did NOT match",
 590                                select_plural (n_computed_checksums)),
 591                      n_mismatched_checksums, n_computed_checksums);
 592             }
 593         }
 594     }
 595
 596   return (n_properly_formatted_lines != 0
 597           && n_mismatched_checksums == 0
 598           && n_open_or_read_failures == 0);
 599 }
 600
 601 int
 602 main (int argc, char **argv)
 603 {
 604   unsigned char bin_buffer_unaligned[DIGEST_BIN_BYTES + DIGEST_ALIGN];
 605   /* Make sure bin_buffer is properly aligned. */
 606   unsigned char *bin_buffer = ptr_align (bin_buffer_unaligned, DIGEST_ALIGN);
 607   bool do_check = false;
 608   int opt;
 609   bool ok = true;
 610   int binary = -1;
 611
 612   /* Setting values of global variables.  */
 613   initialize_main (&argc, &argv);
 614   set_program_name (argv[0]);
 615   setlocale (LC_ALL, "");
 616   bindtextdomain (PACKAGE, LOCALEDIR);
 617   textdomain (PACKAGE);
 618
 619   atexit (close_stdout);
 620
 621   while ((opt = getopt_long (argc, argv, "bctw", long_options, NULL)) != -1)
 622     switch (opt)
 623       {
 624       case 'b':
 625         binary = 1;
 626         break;
 627       case 'c':
 628         do_check = true;
 629         break;
 630       case STATUS_OPTION:
 631         status_only = true;
 632         warn = false;
 633         quiet = false;
 634         break;
 635       case 't':
 636         binary = 0;
 637         break;
 638       case 'w':
 639         status_only = false;
 640         warn = true;
 641         quiet = false;
 642         break;
 643       case QUIET_OPTION:
 644         status_only = false;
 645         warn = false;
 646         quiet = true;
 647         break;
 648       case_GETOPT_HELP_CHAR;
 649       case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 650       default:
 651         usage (EXIT_FAILURE);
 652       }
 653
 654   min_digest_line_length = MIN_DIGEST_LINE_LENGTH;
 655   digest_hex_bytes = DIGEST_HEX_BYTES;
 656
 657   if (0 <= binary && do_check)
 658     {
 659       error (0, 0, _("the --binary and --text options are meaningless when "
 660                      "verifying checksums"));
 661       usage (EXIT_FAILURE);
 662     }
 663
 664   if (status_only & !do_check)
 665     {
 666       error (0, 0,
 667        _("the --status option is meaningful only when verifying checksums"));
 668       usage (EXIT_FAILURE);
 669     }
 670
 671   if (warn & !do_check)
 672     {
 673       error (0, 0,
 674        _("the --warn option is meaningful only when verifying checksums"));
 675       usage (EXIT_FAILURE);
 676     }
 677
 678   if (quiet & !do_check)
 679     {
 680       error (0, 0,
 681        _("the --quiet option is meaningful only when verifying checksums"));
 682       usage (EXIT_FAILURE);
 683     }
 684
 685   if (!O_BINARY && binary < 0)
 686     binary = 0;
 687
 688   if (optind == argc)
 689     argv[argc++] = bad_cast ("-");
 690
 691   for (; optind < argc; ++optind)
 692     {
 693       char *file = argv[optind];
 694
 695       if (do_check)
 696         ok &= digest_check (file);
 697       else
 698         {
 699           int file_is_binary = binary;
 700
 701           if (! digest_file (file, &file_is_binary, bin_buffer))
 702             ok = false;
 703           else
 704             {
 705               size_t i;
 706
 707               /* Output a leading backslash if the file name contains
 708                  a newline or backslash.  */
 709               if (strchr (file, '\n') || strchr (file, '\\'))
 710                 putchar ('\\');
 711
 712               for (i = 0; i < (digest_hex_bytes / 2); ++i)
 713                 printf ("%02x", bin_buffer[i]);
 714
 715               putchar (' ');
 716               if (file_is_binary)
 717                 putchar ('*');
 718               else
 719                 putchar (' ');
 720
 721               /* Translate each NEWLINE byte to the string, "\\n",
 722                  and each backslash to "\\\\".  */
 723               for (i = 0; i < strlen (file); ++i)
 724                 {
 725                   switch (file[i])
 726                     {
 727                     case '\n':
 728                       fputs ("\\n", stdout);
 729                       break;
 730
 731                     case '\\':
 732                       fputs ("\\\\", stdout);
 733                       break;
 734
 735                     default:
 736                       putchar (file[i]);
 737                       break;
 738                     }
 739                 }
 740               putchar ('\n');
 741             }
 742         }
 743     }
 744
 745   if (have_read_stdin && fclose (stdin) == EOF)
 746     error (EXIT_FAILURE, errno, _("standard input"));
 747
 748   exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);
 749 }