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Diffstat (limited to 'src/cksum.c')
| -rw-r--r-- | src/cksum.c | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/src/cksum.c b/src/cksum.c new file mode 100644 index 0000000..97fc706 --- /dev/null +++ b/src/cksum.c @@ -0,0 +1,310 @@ +/* cksum -- calculate and print POSIX checksums and sizes of files + Copyright (C) 1992-2020 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. */ + +/* Written by Q. Frank Xia, qx@math.columbia.edu. + Cosmetic changes and reorganization by David MacKenzie, djm@gnu.ai.mit.edu. + + Usage: cksum [file...] + + The code segment between "#ifdef CRCTAB" and "#else" is the code + which calculates the "crctab". It is included for those who want + verify the correctness of the "crctab". To recreate the "crctab", + do something like the following: + + cc -DCRCTAB -o crctab cksum.c + crctab > crctab.h + + This software is compatible with neither the System V nor the BSD + 'sum' program. It is supposed to conform to POSIX, except perhaps + for foreign language support. Any inconsistency with the standard + (other than foreign language support) is a bug. */ + +#include <config.h> + +/* The official name of this program (e.g., no 'g' prefix). */ +#define PROGRAM_NAME "cksum" + +#define AUTHORS proper_name ("Q. Frank Xia") + +#include <stdio.h> +#include <sys/types.h> +#include <stdint.h> +#include "system.h" +#include "fadvise.h" +#include "xbinary-io.h" + +#ifdef CRCTAB + +# define BIT(x) ((uint_fast32_t) 1 << (x)) +# define SBIT BIT (31) + +/* The generating polynomial is + + 32 26 23 22 16 12 11 10 8 7 5 4 2 1 + G(X)=X + X + X + X + X + X + X + X + X + X + X + X + X + X + 1 + + The i bit in GEN is set if X^i is a summand of G(X) except X^32. */ + +# define GEN (BIT (26) | BIT (23) | BIT (22) | BIT (16) | BIT (12) \ + | BIT (11) | BIT (10) | BIT (8) | BIT (7) | BIT (5) \ + | BIT (4) | BIT (2) | BIT (1) | BIT (0)) + +static uint_fast32_t r[8]; + +static void +fill_r (void) +{ + r[0] = GEN; + for (int i = 1; i < 8; i++) + r[i] = (r[i - 1] << 1) ^ ((r[i - 1] & SBIT) ? GEN : 0); +} + +static uint_fast32_t +crc_remainder (int m) +{ + uint_fast32_t rem = 0; + + for (int i = 0; i < 8; i++) + if (BIT (i) & m) + rem ^= r[i]; + + return rem & 0xFFFFFFFF; /* Make it run on 64-bit machine. */ +} + +int +main (void) +{ + fill_r (); + printf ("static uint_fast32_t const crctab[256] =\n{\n 0x00000000"); + for (int i = 0; i < 51; i++) + { + printf (",\n 0x%08x, 0x%08x, 0x%08x, 0x%08x, 0x%08x", + crc_remainder (i * 5 + 1), crc_remainder (i * 5 + 2), + crc_remainder (i * 5 + 3), crc_remainder (i * 5 + 4), + crc_remainder (i * 5 + 5)); + } + printf ("\n};\n"); + return EXIT_SUCCESS; +} + +#else /* !CRCTAB */ + +# include "long-options.h" +# include "die.h" +# include "error.h" + +/* Number of bytes to read at once. */ +# define BUFLEN (1 << 16) + +static uint_fast32_t const crctab[256] = +{ + 0x00000000, + 0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b, + 0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, + 0x2b4bcb61, 0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, + 0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9, 0x5f15adac, + 0x5bd4b01b, 0x569796c2, 0x52568b75, 0x6a1936c8, 0x6ed82b7f, + 0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3, 0x709f7b7a, + 0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039, + 0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58, + 0xbaea46ef, 0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033, + 0xa4ad16ea, 0xa06c0b5d, 0xd4326d90, 0xd0f37027, 0xddb056fe, + 0xd9714b49, 0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95, + 0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1, 0xe13ef6f4, + 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0, + 0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5, + 0x2ac12072, 0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16, + 0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca, 0x7897ab07, + 0x7c56b6b0, 0x71159069, 0x75d48dde, 0x6b93dddb, 0x6f52c06c, + 0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08, 0x571d7dd1, + 0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba, + 0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b, + 0xbb60adfc, 0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698, + 0x832f1041, 0x87ee0df6, 0x99a95df3, 0x9d684044, 0x902b669d, + 0x94ea7b2a, 0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e, + 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2, 0xc6bcf05f, + 0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34, + 0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80, + 0x644fc637, 0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb, + 0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f, 0x5c007b8a, + 0x58c1663d, 0x558240e4, 0x51435d53, 0x251d3b9e, 0x21dc2629, + 0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5, 0x3f9b762c, + 0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff, + 0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e, + 0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65, + 0xeba91bbc, 0xef68060b, 0xd727bbb6, 0xd3e6a601, 0xdea580d8, + 0xda649d6f, 0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3, + 0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7, 0xae3afba2, + 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71, + 0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74, + 0x857130c3, 0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, + 0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c, 0x7b827d21, + 0x7f436096, 0x7200464f, 0x76c15bf8, 0x68860bfd, 0x6c47164a, + 0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e, 0x18197087, + 0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec, + 0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d, + 0x2056cd3a, 0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce, + 0xcc2b1d17, 0xc8ea00a0, 0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, + 0xdbee767c, 0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18, + 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4, 0x89b8fd09, + 0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662, + 0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf, + 0xa2f33668, 0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4 +}; + +/* Nonzero if any of the files read were the standard input. */ +static bool have_read_stdin; + +/* Calculate and print the checksum and length in bytes + of file FILE, or of the standard input if FILE is "-". + If PRINT_NAME is true, print FILE next to the checksum and size. + Return true if successful. */ + +static bool +cksum (const char *file, bool print_name) +{ + unsigned char buf[BUFLEN]; + uint_fast32_t crc = 0; + uintmax_t length = 0; + size_t bytes_read; + FILE *fp; + char length_buf[INT_BUFSIZE_BOUND (uintmax_t)]; + char const *hp; + + if (STREQ (file, "-")) + { + fp = stdin; + have_read_stdin = true; + xset_binary_mode (STDIN_FILENO, O_BINARY); + } + else + { + fp = fopen (file, (O_BINARY ? "rb" : "r")); + if (fp == NULL) + { + error (0, errno, "%s", quotef (file)); + return false; + } + } + + fadvise (fp, FADVISE_SEQUENTIAL); + + while ((bytes_read = fread (buf, 1, BUFLEN, fp)) > 0) + { + unsigned char *cp = buf; + + if (length + bytes_read < length) + die (EXIT_FAILURE, 0, _("%s: file too long"), quotef (file)); + length += bytes_read; + while (bytes_read--) + crc = (crc << 8) ^ crctab[((crc >> 24) ^ *cp++) & 0xFF]; + if (feof (fp)) + break; + } + + if (ferror (fp)) + { + error (0, errno, "%s", quotef (file)); + if (!STREQ (file, "-")) + fclose (fp); + return false; + } + + if (!STREQ (file, "-") && fclose (fp) == EOF) + { + error (0, errno, "%s", quotef (file)); + return false; + } + + hp = umaxtostr (length, length_buf); + + for (; length; length >>= 8) + crc = (crc << 8) ^ crctab[((crc >> 24) ^ length) & 0xFF]; + + crc = ~crc & 0xFFFFFFFF; + + if (print_name) + printf ("%u %s %s\n", (unsigned int) crc, hp, file); + else + printf ("%u %s\n", (unsigned int) crc, hp); + + if (ferror (stdout)) + die (EXIT_FAILURE, errno, "-: %s", _("write error")); + + return true; +} + +void +usage (int status) +{ + if (status != EXIT_SUCCESS) + emit_try_help (); + else + { + printf (_("\ +Usage: %s [FILE]...\n\ + or: %s [OPTION]\n\ +"), + program_name, program_name); + fputs (_("\ +Print CRC checksum and byte counts of each FILE.\n\ +\n\ +"), stdout); + fputs (HELP_OPTION_DESCRIPTION, stdout); + fputs (VERSION_OPTION_DESCRIPTION, stdout); + emit_ancillary_info (PROGRAM_NAME); + } + exit (status); +} + +int +main (int argc, char **argv) +{ + int i; + bool ok; + + initialize_main (&argc, &argv); + set_program_name (argv[0]); + setlocale (LC_ALL, ""); + bindtextdomain (PACKAGE, LOCALEDIR); + textdomain (PACKAGE); + + atexit (close_stdout); + + /* Line buffer stdout to ensure lines are written atomically and immediately + so that processes running in parallel do not intersperse their output. */ + setvbuf (stdout, NULL, _IOLBF, 0); + + parse_gnu_standard_options_only (argc, argv, PROGRAM_NAME, PACKAGE, Version, + true, usage, AUTHORS, (char const *) NULL); + + have_read_stdin = false; + + if (optind == argc) + ok = cksum ("-", false); + else + { + ok = true; + for (i = optind; i < argc; i++) + ok &= cksum (argv[i], true); + } + + if (have_read_stdin && fclose (stdin) == EOF) + die (EXIT_FAILURE, errno, "-"); + return ok ? EXIT_SUCCESS : EXIT_FAILURE; +} + +#endif /* !CRCTAB */ |