Mercurial > hg > toybox
annotate toys/posix/cksum.c @ 674:7e846e281e38
New build infrastructure to generate FLAG_ macros and TT alias, #define FOR_commandname before #including toys.h to trigger it. Rename DEFINE_GLOBALS() to just GLOBALS() (because I could never remember if it was DECLARE_GLOBALS). Convert existing commands to use new infrastructure, and replace optflag constants with FLAG_ macros where appropriate.
| author | Rob Landley <rob@landley.net> |
|---|---|
| date | Mon, 08 Oct 2012 00:02:30 -0500 |
| parents | 6df4ccc0acbe |
| children | 786841fdb1e0 |
| rev | line source |
|---|---|
| 333 | 1 /* vi: set sw=4 ts=4: |
| 2 * | |
| 3 * cksum.c - produce crc32 checksum value for each input | |
| 4 * | |
| 5 * Copyright 2008 Rob Landley <rob@landley.net> | |
| 6 * | |
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7 * See http://opengroup.org/onlinepubs/9699919799/utilities/cksum.html |
| 333 | 8 |
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9 USE_CKSUM(NEWTOY(cksum, "IPLN", TOYFLAG_BIN)) |
| 333 | 10 |
| 11 config CKSUM | |
| 12 bool "cksum" | |
| 13 default y | |
| 14 help | |
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15 usage: cksum [-IPLN] [file...] |
| 336 | 16 |
| 333 | 17 For each file, output crc32 checksum value, length and name of file. |
| 18 If no files listed, copy from stdin. Filename "-" is a synonym for stdin. | |
| 336 | 19 |
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20 -L Little endian (defaults to big endian) |
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21 -P Pre-inversion |
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22 -I Skip post-inversion |
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23 -N Do not include length in CRC calculation |
| 333 | 24 */ |
| 25 | |
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7e846e281e38
New build infrastructure to generate FLAG_ macros and TT alias, #define FOR_commandname before #including toys.h to trigger it. Rename DEFINE_GLOBALS() to just GLOBALS() (because I could never remember if it was DECLARE_GLOBALS). Convert existing commands to use new infrastructure, and replace optflag constants with FLAG_ macros where appropriate.
Rob Landley <rob@landley.net>
parents:
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changeset
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26 #define FOR_cksum |
| 333 | 27 #include "toys.h" |
| 28 | |
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New build infrastructure to generate FLAG_ macros and TT alias, #define FOR_commandname before #including toys.h to trigger it. Rename DEFINE_GLOBALS() to just GLOBALS() (because I could never remember if it was DECLARE_GLOBALS). Convert existing commands to use new infrastructure, and replace optflag constants with FLAG_ macros where appropriate.
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29 GLOBALS( |
| 333 | 30 unsigned crc_table[256]; |
| 31 ) | |
| 32 | |
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33 static unsigned cksum_be(unsigned crc, unsigned char c) |
| 333 | 34 { |
| 35 return (crc<<8)^TT.crc_table[(crc>>24)^c]; | |
| 36 } | |
| 37 | |
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38 static unsigned cksum_le(unsigned crc, unsigned char c) |
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39 { |
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40 return TT.crc_table[(crc^c)&0xff] ^ (crc>>8); |
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41 } |
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42 |
| 333 | 43 static void do_cksum(int fd, char *name) |
| 44 { | |
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45 unsigned crc = (toys.optflags&4) ? 0xffffffff : 0; |
| 333 | 46 uint64_t llen = 0, llen2; |
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47 unsigned (*cksum)(unsigned crc, unsigned char c); |
| 333 | 48 |
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49 |
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50 cksum = (toys.optflags&2) ? cksum_le : cksum_be; |
| 333 | 51 // CRC the data |
| 52 | |
| 53 for (;;) { | |
| 54 int len, i; | |
| 55 | |
| 56 len = read(fd, toybuf, sizeof(toybuf)); | |
| 57 if (len<0) { | |
| 58 perror_msg("%s",name); | |
| 59 toys.exitval = EXIT_FAILURE; | |
| 60 } | |
| 61 if (len<1) break; | |
| 62 | |
| 63 llen += len; | |
| 64 for (i=0; i<len; i++) crc=cksum(crc, toybuf[i]); | |
| 65 } | |
| 66 | |
| 67 // CRC the length | |
| 68 | |
| 69 llen2 = llen; | |
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70 if (!(toys.optflags&1)) { |
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71 while (llen) { |
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72 crc = cksum(crc, llen); |
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73 llen >>= 8; |
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74 } |
| 333 | 75 } |
| 76 | |
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77 printf("%u %"PRIu64, (toys.optflags&8) ? crc : ~crc, llen2); |
| 333 | 78 if (strcmp("-", name)) printf(" %s", name); |
| 79 xputc('\n'); | |
| 80 } | |
| 81 | |
| 82 void cksum_main(void) | |
| 83 { | |
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84 crc_init(TT.crc_table, toys.optflags&2); |
| 333 | 85 loopfiles(toys.optargs, do_cksum); |
| 86 } |