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   1 #include "config.h"
   2 #include <stdio.h>
   3 #include <string.h>
   4
   5 /**
   6  * crcsync - routines to use crc for an rsync-like protocol.
   7  *
   8  * This is a complete library for synchronization using a variant of the
   9  * rsync protocol.
  10  *
  11  * Example:
  12  *      // Calculate checksums of file (3-arg mode)
  13  *      // Or print differences between file and checksums (4+ arg mode)
  14  *      #include <ccan/crcsync/crcsync.h>
  15  *      #include <ccan/tal/grab_file/grab_file.h>
  16  *      #include <ccan/tal/tal.h>
  17  *      #include <stdio.h>
  18  *      #include <stdlib.h>
  19  *      #include <err.h>
  20  *
  21  *      static void print_result(long result)
  22  *      {
  23  *              if (result < 0)
  24  *                      printf("MATCHED CRC %lu\n", -result - 1);
  25  *              else if (result > 0)
  26  *                      printf("%lu literal bytes\n", result);
  27  *      }
  28  *
  29  *      int main(int argc, char *argv[])
  30  *      {
  31  *              size_t len, used, blocksize;
  32  *              char *file;
  33  *              struct crc_context *ctx;
  34  *              uint64_t *crcs;
  35  *              long res, i;
  36  *
  37  *              if (argc < 3 || (blocksize = atoi(argv[1])) == 0)
  38  *                      errx(1, "Usage: %s <blocksize> <file> <crc>...\n"
  39  *                           "OR: %s <blocksize> <file>", argv[0], argv[0]);
  40  *
  41  *              file = grab_file(NULL, argv[2]);
  42  *              if (!file)
  43  *                      err(1, "Opening file %s", argv[2]);
  44  *              len = tal_count(file) - 1;
  45  *
  46  *              if (argc == 3) {
  47  *                      // Short form prints CRCs of file for use in long form.
  48  *                      used = (len + blocksize - 1) / blocksize;
  49  *                      crcs = malloc(used * sizeof(crcs[0]));
  50  *                      crc_of_blocks(file, len, blocksize, 32, crcs);
  51  *                      for (i = 0; i < used; i++)
  52  *                              printf("%llu ", (long long)crcs[i]);
  53  *                      printf("\n");
  54  *                      return 0;
  55  *              }
  56  *
  57  *              crcs = malloc((argc - 3) * sizeof(uint32_t));
  58  *              for (i = 0; i < argc-3; i++)
  59  *                      crcs[i] = atoi(argv[3+i]);
  60  *
  61  *              ctx = crc_context_new(blocksize, 32, crcs, argc-3, 0);
  62  *              for (used = 0; used < len; ) {
  63  *                      used += crc_read_block(ctx, &res, file+used, len-used);
  64  *                      print_result(res);
  65  *              }
  66  *              while ((res = crc_read_flush(ctx)) != 0)
  67  *                      print_result(res);
  68  *
  69  *              return 0;
  70  *      }
  71  *
  72  * License: LGPL (v2.1 or any later version)
  73  * Author: Rusty Russell <rusty@rustcorp.com.au>
  74  */
  75 int main(int argc, char *argv[])
  76 {
  77         if (argc != 2)
  78                 return 1;
  79
  80         if (strcmp(argv[1], "depends") == 0) {
  81                 printf("ccan/crc\n");
  82                 return 0;
  83         }
  84         if (strcmp(argv[1], "testdepends") == 0) {
  85                 printf("ccan/array_size\n");
  86                 return 0;
  87         }
  88         if (strcmp(argv[1], "ccanlint") == 0) {
  89                 /* We actually depend on the GPL crc routines, so not really LGPL :( */
  90                 printf("license_depends_compat FAIL\n");
  91                 return 0;
  92         }
  93
  94         return 1;
  95 }