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Diffstat (limited to 'src/cksum.c')
| -rw-r--r-- | src/cksum.c | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/src/cksum.c b/src/cksum.c new file mode 100644 index 000000000..df9c3130b --- /dev/null +++ b/src/cksum.c @@ -0,0 +1,274 @@ +/* cksum -- calculate and print POSIX.2 checksums and sizes of files + Copyright (C) 1992 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 2, 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, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ + +/* 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 following: + + cc -DCRCTAB -o crctab cksum.c + crctab > crctab.h + + As Bruce Evans pointed out to me, the crctab in the sample C code + in 4.9.10 Rationale of P1003.2/D11.2 is represented in reversed order. + Namely, 0x01 is represented as 0x80, 0x02 is represented as 0x40, etc. + The generating polynomial is crctab[0x80]=0xedb88320 instead of + crctab[1]=0x04C11DB7. But the code works only for a non-reverse order + crctab. Therefore, the sample implementation is wrong. + + This software is compatible with neither the System V nor the BSD + `sum' program. It is supposed to conform to P1003.2/D11.2, + except foreign language interface (4.9.5.3 of P1003.2/D11.2) support. + Any inconsistency with the standard except 4.9.5.3 is a bug. */ + +#ifdef CRCTAB + +#include <stdio.h> + +#define BIT(x) ( (unsigned long)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)); + +unsigned long r[8]; + +void +fill_r () +{ + int i; + + r[0] = GEN; + for (i = 1; i < 8; i++) + r[i] = (r[i - 1] & SBIT) ? (r[i - 1] << 1) ^ r[0] : r[i - 1] << 1; +} + +unsigned long +remainder (m) + int m; +{ + unsigned long rem = 0; + int i; + + for (i = 0; i < 8; i++) + if (BIT (i) & m) + rem = rem ^ r[i]; + + return rem & 0xFFFFFFFF; /* Make it run on 64-bit machine. */ +} + +void +main () +{ + int i; + + fill_r (); + printf ("unsigned long crctab[256] = {\n 0x0"); + for (i = 0; i < 51; i++) + { + printf (",\n 0x%08X, 0x%08X, 0x%08X, 0x%08X, 0x%08X", + remainder (i * 5 + 1), remainder (i * 5 + 2), remainder (i * 5 + 3), + remainder (i * 5 + 4), remainder (i * 5 + 5)); + } + printf ("\n};\n"); + exit (0); +} + +#else /* !CRCTAB */ + +#include <stdio.h> +#include <sys/types.h> +#include "system.h" + +/* Number of bytes to read at once. */ +#define BUFLEN (1 << 16) + +unsigned long crctab[256] = +{ + 0x0, + 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 +}; + +/* The name this program was run with. */ +char *program_name; + +/* Nonzero if any of the files read were the standard input. */ +int 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 nonzero, print FILE next to the checksum and size. + Return 0 if successful, -1 if an error occurs. */ + +int +cksum (file, print_name) + char *file; + int print_name; +{ + unsigned char buf[BUFLEN]; + unsigned long crc = 0; + long length = 0; + long bytes_read; + register FILE *fp; + + if (!strcmp (file, "-")) + { + fp = stdin; + have_read_stdin = 1; + } + else + { + fp = fopen (file, "r"); + if (fp == NULL) + { + error (0, errno, "%s", file); + return -1; + } + } + + while ((bytes_read = fread (buf, 1, BUFLEN, fp)) > 0) + { + unsigned char *cp = buf; + + length += bytes_read; + while (bytes_read--) + crc = (crc << 8) ^ crctab[((crc >> 24) ^ *(cp++)) & 0xFF]; + } + + if (ferror (fp)) + { + error (0, errno, "%s", file); + if (strcmp (file, "-")) + fclose (fp); + return -1; + } + + if (strcmp (file, "-") && fclose (fp) == EOF) + { + error (0, errno, "%s", file); + return -1; + } + + bytes_read = length; + while (bytes_read > 0) + { + crc = (crc << 8) ^ crctab[((crc >> 24) ^ bytes_read) & 0xFF]; + bytes_read >>= 8; + } + + crc = ~crc & 0xFFFFFFFF; + + printf ("%10lu %8ld", crc, length); + if (print_name) + printf (" %s", file); + putchar ('\n'); + + return 0; +} + +void +main (argc, argv) + int argc; + char **argv; +{ + int errors = 0; + + program_name = argv[0]; + have_read_stdin = 0; + + if (argc == 1) + { + if (cksum ("-", 0) < 0) + errors = 1; + } + else + { + int optind; + + for (optind = 1; optind < argc; ++optind) + if (cksum (argv[optind], 1) < 0) + errors = 1; + } + + if (have_read_stdin && fclose (stdin) == EOF) + error (1, errno, "-"); + exit (errors); +} + +#endif /* !CRCTAB */ |