sca_read.c

Solaris操作系统下的过滤驱动程序, C源码程序.

/*
 * Copyright (c) 1997-2003 Erez Zadok
 * Copyright (c) 2001-2003 Stony Brook University
 * Copyright (c) 1997-2000 Columbia University
 *
 * For specific licensing information, see the COPYING file distributed with
 * this package, or get one from ftp://ftp.filesystems.org/pub/fist/COPYING.
 *
 * This Copyright notice must be kept intact and distributed with all
 * fistgen sources INCLUDING sources generated by fistgen.
 */
/*
 *  $Id: sca_read.c,v 1.5 2002/12/27 20:19:06 ezk Exp $
 */
#include <stdio.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <errno.h>
#include <limits.h>
#include <string.h>

#include "sca_aux.h"
#include "sca_code.h"	/* replace with your definitions of en/decode _page */


int
decode_file(char *name)
{
  char idx[MAXPATHLEN];
  int srcfd;
  struct fistfs_header hdr;
  int i, len;
  unsigned char *out;

  if (name == NULL)
    return(-1);

  if ((srcfd = open(name, O_RDONLY)) < 0)
    return(-1);

  sprintf(idx, "%s.idx", name);
  if ((read_idx(idx, &hdr)) < 0)
    return(-1); /* read the header */

  for(i=0; i<hdr.num_pages; i++) {
    if ((get_page(srcfd, &hdr, i, &out, &len)) < 0) {
      fprintf(stderr, "get_page returns error!\n");
      return(-1);
    }

    if (len > chunksize) {
      fprintf(stderr, "***decode returned %d bytes\n", len);
    }
    write(1, out, len);
    free(out);
  }

  if(do_fast_tails) {		/* See if there unencoded data at the end */
    /* This get_page will return 0 if there is no unencoded tail */
    if ((get_page(srcfd, &hdr, i, &out, &len)) < 0) {
      fprintf(stderr,"get_page returns error!\n");
      return(-1);
    }
    write(1, out, len);
    free(out);
  }
  return(0);
}


void
usage(const char *progname)
{
  fprintf(stderr,
	  "Usage: %s [-c chunksize] [-d] [-f] file1 [file2 file3 ...]\n",
	  progname);
}


int
main(int argc, char **argv)
{
  int i, rc, cnt = 0;
  int debug = 0;
  char *name;

  if (argc < 2) {
    usage(argv[0]);
    exit(1);
  }

  while((i = getopt(argc, argv, "c:df")) != EOF) {
    switch(i) {
    case 'c':
      chunksize = atoi(optarg);
      if (chunksize < 0) {
	fprintf(stderr, "Please use a positive chunk size\n");
	exit(1);
      }
      break;
    case 'f':
      do_fast_tails = 1;
      break;
    case 'd':
      debug = 1;
      break;
    default:
      usage(argv[0]);
      exit(1);
    }
  }

  for(i=optind; i<argc; i++) {
    name = strdup(argv[i]);
    if ((rc = decode_file(argv[i])) < 0) {
      fprintf(stderr, "\tError decoding %s (%d)\n", argv[i], rc);
      cnt++;
    }
    free(name);
  }

  if (debug) {
    fprintf(stderr,"encodes: %d\n", encode_counter);
    fprintf(stderr,"decodes: %d\n", decode_counter);
    fprintf(stderr,"writes:  %d\n", write_counter);
  }
  exit(cnt);
}